Commodore 128

The Commodore 128 (C128, CBM 128, C=128) home/personal computer was the last 8-bit machine commercially released by Commodore Business Machines (CBM). Introduced in January of 1985 at the CES in Las Vegas, it appeared three years after its predecessor, the bestselling Commodore 64. The primary hardware designer of the C128 was Bil Herd.

The C128 was a significantly expanded successor to the C64 and unlike the earlier Plus/4 it remained compatible. The new machine featured 128 KB of RAM (externally expandable to 640 KB) and an 80-column RGB monitor output (driven by the 8563 VDC chip with 16 KB dedicated video RAM, although following the release of the 128D later 'flat' 128s had 64 KB of VRAM[citation needed]), as well as a redesigned case/keyboard with a numeric keypad. The 128's power supply was vastly improved over the 64's troublesome design. It was much larger, with cooling vents and a fuse to protect it from blowing up. Instead of the 6510 CPU of the C64, the C128 incorporated a two-CPU design. The primary CPU, the 8502, was a slightly improved version of the 6510; its main addition was the ability to run at a 2 MHz clock rate (being quite beneficial to the 80 column display, but making it difficult to display a second signal to a second monitor, such as that used for a 40 column display). The second CPU was a Zilog Z80 which was used for ensuring CP/M compatibility and for mode-selection of the computer upon boot-up. The two processors could not run concurrently, thus the C128 was not a multiprocessing system.

The C128 had three modes of operation: C128 Mode (native mode), which ran at 1 or 2 MHz with the 8502 CPU and had both 40- and 80-column text modes available; CP/M Mode, which used the Z80 second CPU in either 40- or 80-column text mode; and C64 Mode, which was very nearly 100% compatible with the earlier computer. None of these modes would have been possible as implemented on the C128 without the Z80 chip. The Z80 controls the bus on initial boot-up and checks to see if there are any C64/C128 cartridges present, and if the Commodore key (C64-mode selector) is active on boot-up. Based on what it finds, it will switch to the appropriate mode of operation.

Some 128s suffered from a reliability problem caused by the electromagnetic shield over the internal board. The shield had fingers that rested on the top of the major chips to conduct heat into the shield which then acted as a large heatsink. A combination of poor contact and the fact that plastic encased chips do not lose heat that way plus the shield being made from mu-metal (a poor heat conductor) saw some chips overheat and fail. The SID sound chip was particularly vulnerable in this respect as it operated from a 9 volt supply. The situation could be vastly improved by removing the shield completely.

C128 Mode
C128 Main board

While the C64's graphics and sound capabilities were generally considered excellent, the popular home computer was the subject of a number of perennial criticisms. The 40-column VIC-II video display, while excellent for gaming, was often considered inadequate for productivity applications such as word processing. The lack of a numeric keypad was also an issue with some office suite software. Furthermore, the 2.0 revision of Commodore BASIC that was incorporated into the C64 was quite limited, and lacked keywords to handle the system's graphical and sound capabilities. These features had to be accessed via terse and potentially cryptic PEEK and POKE commands, or by custom-written machine language routines. A great improvement was the addition of a reset button on the side of the computer, next to the joystick ports. Finally, the C64's 1541 disk drive was almost universally condemned as slow and unreliable in comparison to the swifter and more capacious Commodore 1581.

The designers of the C128 succeeded in rectifying most of these concerns. A new chip, the VDC, provided the C128 with an 80-column color CGA-compatible display (also called RGBI for RGB plus Intensity). The new 8502 CPU was completely backward-compatible with the C64's 6510, but could run at double the speed if desired. However, the VIC-II chip which controlled the 40-column display could not operate at the faster clock rate, so the 40 column display is not available in Fast mode. A numeric keypad was added to the keyboard, as were various other keys. The C64's rudimentary BASIC 2.0 was replaced with the far more flexible and powerful BASIC 7.0, which included keywords designed specifically to take advantage of the machine's capabilities, and also incorporated a sprite editor and machine language monitor. The screen editor was further improved. A reset button was added to the system.

Three new disk drives were introduced in conjunction with the C128, the 1570, 1571, and 3.5 inch 1581 drives promising far faster transfer speeds via a new 'burst mode'. With these three drives, more complex drive data arrangements were also made available to Commodore users in the nature of 'track and sector' oriented subdirectories, a feature not available to PC users, who instead had to convolute their file allocation tables to do the same thing. The disk drives also had more on-board RAM than their predecessors, the 1540 and 1541 drives.

The C128 also had twice the RAM of the C64, and a far higher proportion was available for BASIC programming, due to the new MMU bankswitching chip. This feature made it possible for BASIC program code to be stored separately from variables, greatly enhancing the machine's ability to handle complex programs.

The C128's greater hardware capabilities, especially the increased RAM, screen display resolution, and serial bus speed, made it the preferred platform for running the GEOS graphical operating system.

CP/M Mode

The second of the C128's two CPUs was the Zilog Z80, which allowed the C128 to run CP/M; the machine came with CP/M 3.0, aka CP/M Plus (backward compatible with CP/M 2.2) and ADM31/3A terminal emulation. To make a large application software library instantly available at launch, the Commodore 128 CP/M and accompanying 1571 floppy disk drive was designed to run almost all Kaypro-specific CP/M software without modification.

Unfortunately, the C128 ran CP/M noticeably slower than most dedicated CP/M systems, as the Z80 processor ran at an effective speed of only 2 MHz (instead of the more common 4–6 MHz) and because it used CP/M 3.0, whose complexity made it inherently slower than the earlier, more widespread, CP/M 2.2 system. From the source code of the C128 CP/M implementation, it is clear that the engineers originally planned to make it possible to run CP/M in the 'fast' mode as well, with the 40-column output turned off and the Z80 running at an effective 4 MHz; however, this did not work on the released C128 hardware.

A possibly unique feature of the C128 among CP/M systems was that some of the low-level BIOS services were executed by the 8502 chip instead of the Z80. The latter transferred control to the 8502 after having placed the pertinent parameter values in designated memory locations. The Z80 then turned itself off, being awoken by the 8502 at completion of the BIOS routine, with status value(s) available in RAM for inspection.

C64 Mode

By incorporating the original C64 BASIC and KERNAL ROMs in their entirety (16 KB total), the C128 achieves almost 100% compatibility with C64 software. The C64 mode can be accessed in one of three ways:

* Hold down the Commodore logo key when booting the system
* Enter the GO64 command in BASIC 7.0 immediate mode
* Boot with a C64 cartridge plugged in

Some of the few C64 programs that fail on a C128 run correctly when the CAPS LOCK key is pressed down (or the ASCII/National key on international C128 models). This has to do with the larger built-in I/O port of the C128's CPU. Whereas the SHIFT LOCK key found on both C64 and C128 is simply a mechanical latch for the left SHIFT key, the CAPS LOCK key on the C128 can be read via the 8502's built-in I/O port. A few C64 programs are confused by this extra I/O bit; keeping the CAPS LOCK key in the down position will force the I/O line low, matching the C64's configuration and resolving the issue.

A handful of C64 programs wrote to $D030 (53296), often as part of a loop initializing the VIC-II chip registers. This memory-mapped register, unused in the C64, operated as a selector for 2 MHz mode in the C128. Since it was not disabled in C64 mode, an inadvertent write could blank the 40-column display by putting the CPU into fast mode. Fortunately, very few programs suffered from this flaw. In July 1986, COMPUTE!'s Gazette published a type-in program that exploited this minor incompatibility, by using a raster interrupt to enable fast mode when the bottom of the visible screen was reached, and then disable it when screen rendering began again at the top. By using fast mode during the vertical blank period, standard video display was maintained while increasing overall execution speed by about 20%. [1] [2]

An easy way to tell the C128's C64 mode and a real C64 apart, typically used from within a running program, is to write a value different from $FF (255) to memory address $D02F (53295), which is used to decode the extra keys of the C128 (the numerical keypad and some other keys). On the 64 this memory location will always contain the value $FF no matter what was written to it, but on a C128 in 64 mode the value of the location—a memory-mapped register—can be changed. Thus, checking the location's value after writing to it will reveal the actual hardware platform.

RAM setup

To handle the relatively large amounts of installable RAM, tenfold the 8502's 64 KB address space, the C128 used the 8722 MMU chip to create different memory maps, in which different combinations of RAM and ROM would appear according to bit patterns written into the MMU's confguration register. While the MMU was designed to handle more than 128 KB, the versions that were actually produced and used in the C128 cannot do so.

Although referred to as RAM expanders, Commodore's RAM Expansion Units were not expansion devices at all, as they utilized an external DMA controller to copy bytes between the C-128's RAM and the RAM in the 'expansion unit.' This function was essentially independent of the MMU's memory control features.

Commodore 128D
A Commodore 128D with a Commodore-brand RGB monitor and Commodore 1581 Floppy Disk Drive

In the autumn of 1985, Commodore released to the European market an updated version of the C128 with a redesigned chassis. Called the Commodore 128D, this new European model sported a plastic chassis with a carrying handle on the side, incorporated a 1571 Disk Drive into the main chassis, replaced the built-in keyboard with a detachable one, and added a cooling fan.

In addition to being less bulky than the C128's built-in keyboard, the detachable keyboard of the C128D was lighter in weight, and featured two folding legs for increasing the typing angle.

The following summer, Commodore released the C128D in North America with numerous enhancements. Outside, the C128D boasted an upgraded steel chassis, but lost the carrying handle. Inside, the C128D ROMs contained several bug fixes, and the 8563 VDC chip (in the C128DCR, the 8568) was equipped with the maximum capacity 64 KB of video RAM – four times that of the original C128. This permitted the C128D to do higher-resolution graphics with more colors in RGB mode, although very little software took advantage of this. With or without the extra RAM, the VDC's high-resolution graphics modes were inaccessible from the C128's BASIC. They could only be utilized by calls to screen editor ROM primitive data types (or their assembly language equivalents), or via third-party BASIC language extensions. The most popular such toolkit was Free Spirit Software's 'BASIC 8', which added high-resolution VDC graphics commands to CBM BASIC. BASIC 8 was available on two disks (editor disk and runtime disk) and with a ROM chip for installation in the C128's internal Function ROM socket.

Commodore later released a streamlined version of the C128D, called the Commodore 128DCR (CR for cost reduced), which was marketed in North America. In the C128DCR, Commodore consolidated some of the internal components to save production costs, but also improved heat dissipation to decrease reliance on active cooling.

Market performance

Because the C128 would run virtually all C64 software, and because the next-generation, 32/16-bit home computers, primarily the Commodore Amiga and Atari ST, were gaining ground, relatively little software for the C128's native mode appeared (probably on the order of 100–200 fully commercial titles, plus the usual share of public domain and magazine type-in programs). While the C128 sold a total number of 4 million units between 1985 and 1989, its popularity paled in comparison to that of its predecessor. This has been blamed on the lack of native software and on Commodore's less-aggressive marketing, which was mostly focused on the Amiga. An additional explanation may be found in the fact that the C64 sold huge numbers to people primarily interested in computer games, which the more expensive C128 didn't add much value towards improving (with the exception of a few Infocom text adventures). The C128 was certainly a better business machine than the C64, but not really a better gaming machine, and people who wanted business machines bought IBM PC clones almost exclusively by the time the C128 was released. With its advanced BASIC programming language, CP/M compatibility and 'user-friendly' native software packages such as Jane, Commodore attempted to create a low-end business market for the 128, branding it a 'Personal Computer' on the case, but this strategy was not successful in the face of low-cost IBM-compatibles like the Leading Edge Model D and Tandy 1000 that, in some cases, sold for less than a complete 128 system. There was a professional-level CAD program, Home Designer by BRiWALL, but again, most of this work was done on PCs by the 128s era. The main reason that the C128 still sold fairly well was probably that it was a much better machine for hobbyist programming than the C64.

Also, when the C128(D/DCR) was discontinued in 1989, it was reported to cost nearly as much to manufacture as the 16-bit Amiga 500, even though the C128D had to sell for several hundred dollars less to keep the Amiga's high-value marketing image intact.

Bil Herd commented on the Wikipedia C128 article, stating: 'We considered the C128 to be a holding action until the next generation computers arrived, we were trying to up the game as far as expectations for new machines and buy a year, two at the max in the process. In that we exceeded our initial goals but probably due in part to Commodore's lackluster follow through on marketing and selling the Amiga.'[citation needed]

C128's hidden features
The 40 column version of the C128 Easter egg screen, with a listing of, and a message from, the machine's main developers. Notice the term 'herdware', named after Bil Herd.

* Easter egg: Entering the command 'SYS 32800,123,45,6' in native mode reveals the 40-column screen shown to the right:
* The Commodore 128's BASIC 7.0, the programming language which comes built-in with the computer, can be crashed or cause the computer to reboot by executing PRINT''+-X (where X is any integer), depending on the number entered for X. This bug is present in all known versions of Microsoft's 6502 BASIC interpreter, including the BASIC of all other 8-bit Commodore machines, as well as Applesoft BASIC.
* Entering the keywords QUIT or OFF will produce an '?UNIMPLEMENTED COMMAND ERROR'. These commands are holdovers from a planned but never produced LCD-display portable computer and were intended to exit from the BASIC interpreter and to ignore keyboard input during sensitive program execution, respectively.
* The earlier ROM revision of the C128 includes a rather obvious bug. When in 'CAPS LOCK' mode, each of the alphabetic keys type properly in upper-case except the 'q', which remains lower-case.
* Multiple zero page and CPU stack locations can be defined by twiddling some bits in the C128's MMU, which theoretically would make multitasking a possibility. In practice, the lack of hardware memory protection would create a difficult-to-manage environment in which to run a preemptive kernel.
* Grounding the cartridge port's /EXROM and/or /GAME lines will cause the computer to automatically start up in C64 mode. This design faithfully duplicates the C64 behavior when a cartridge (such as Simons' BASIC) is plugged into the port and asserts either of these lines. C128 mode cartridges are recognized and started by the kernal polling defined locations in the memory map.

Specifications

* CPUs:
o MOS Technology 8502 @ 2 MHz (1 MHz selectable for C64 compatibility mode)
o Zilog Z80 @ 4 MHz (effectively running at 2 MHz due to stopping half the time to allow VIC-II video chip access to system bus)
* MMU: Memory Management Unit controls 8502/Z80 processor selection; ROM/RAM banking; common RAM areas; relocation of zero page and stack
* RAM: 128 KB system RAM, 2 KB 4-bit dedicated color RAM (for the VIC-II E), 16 KB or 64 KB dedicated video RAM (for the VDC), up to 512 KB REU expansion RAM
* ROM: 72 KB (28 KB BASIC 7.0, 4 KB MLM, 8 KB C128 KERNAL, 4 KB screen editor, 4 KB Z80 BIOS, ca. 9 KB C64 BASIC 2.0, ca. 7 KB C64 KERNAL, 4 KB C64 (or international) character generator, 4 KB C128 (or national) character generator) – expandable by 32 KB Internal Function ROM (optional; for placement in motherboard socket) and/or 32KB External Function ROM (optional; for placement in REU socket)
* Video:
o MOS 8564/8566 VIC-II E (NTSC/PAL) for 40-column composite video (a TV set can be used instead of a monitor if desired)
+ Direct register access through memory-mapped I/O
+ Text mode: 40Ṫ25, 16 colors
+ Graphics modes: 160Ṫ200, 320Ṫ200
+ 8 hardware sprites
+ 2 KB dedicated 4-bit color RAM, otherwise uses main memory as video RAM
o MOS 8563 VDC (or, in C128DCR, the 8568) for 80-column digital RGBI component video, compatible with IBM PC CGA monitors, monochrome display also possible on composite video monitors; usable with TV sets only when the set has SCART and/or baseband video-in sockets in addition to the antenna connector. Color is possible through SCART, only monochrome through baseband video-in.
+ Indirect register access (address register, data register in mapped memory)
+ Text mode: Fully programmable, typically 80Ṫ25 or 80x50, 16 colors (not the same as those of the VIC-II)
+ Graphics modes: Fully programmable, typical modes are 320x200, 640Ṫ200, and 640Ṫ400 (interlaced).
+ No hardware sprites
+ 16 KB dedicated video RAM (64 KB standard in C128DCR, C128/C128D was upgradable to 64 KB), accessible to the CPU only in a doubly indirect method (address register, data register on VDC, which in turn are addressed through address register, data register in mapped memory)
+ limited blitter functionality helps to alleviate this RAM bottleneck
* Sound:
o MOS 6581 SID (or, in the C128DCR, the MOS 8580 SID) synthesizer chip
+ 3 voices, ADSR-controllable
+ Standard SID waveforms (triangle, sawtooth, variable pulse, noise, and certain combined modes)
+ Multi-mode filter
+ 3 ring modulators
+ Cost-reduced and noise-reduced version of C64's MOS 6581; some early C128s actually have 6581s
* I/O Ports:
o All the ports of C64 —100% compatible— plus the following:
o Higher speed possible on the serial bus
o Expansion port more flexibly programmable
o RGBI video output (DB9-connector, logically similar to the IBM PC CGA connector, but with an added monochrome composite signal. This added signal causes a minor incompatibility with certain CGA monitors that can be rectified by breaking off pin 7 from the plug at one end of the connecting cable.)

(Info: Wikipidea)

Commodore 64

Released August 1982
Discontinued April 1994
Processor MOS Technology 6510 @ 1.02 MHz (NTSC version) / 0.99MHz (PAL version)
Memory 64 KiB
OS Commodore BASIC 2.0


The Commodore 64 is the best selling single personal computer model of all time. Released in August 1982 by Commodore Business Machines, the Commodore 64 is commonly referred to as the C64 (sometimes written C= 64 to mimic the Commodore company logo) and occasionally known as CBM 64 (its model designation), C-64 or VIC-64 (a label used by some users, magazine writers, third party advertisements and also by Commodore in Sweden). The original Commodore 64 casing has affectionately been nicknamed the 'breadbox' and 'bullnose' due to its shape. Introduced by Commodore Business Machines in August 1982 at a price of USDollar595, it offered 64 kibibytes of RAM with sound and graphics performance that were superior to IBM-compatible computers of that time. During the Commodore 64's lifetime (between 1982 and 1994), sales totaled around 17 million units.

Unlike computers that were distributed only through authorized dealers, Commodore also targeted department stores and toy stores. The unit could be plugged directly into a television set to play games, giving it much of the appeal of dedicated video game consoles like the Atari 2600. Its affordable pricing contributed to the video game market crash of 1983.

Approximately 10,000 commercial software titles were made for the Commodore 64 including development tools, office applications, and games. The machine is also credited with popularizing the computer demo scene. The Commodore 64 is still used today by many computer hobbyists, and emulators (see here for a list) allow anyone with a modern computer (or even smartphones) to run these programs on their desktop (with varying degrees of success and functionality).

The Commodore 64 is commonly seen as an icon of the 1980s. An example is the introductory movie of the video game Grand Theft Auto: Vice City, which features a Commodore 64 screen which later reveals the Rockstar North logo.


History

In January 1981, MOS Technology, Inc., Commodore's integrated circuit design subsidiary, initiated a project to design the graphic and audio chips for a next generation video game console. Design work for the chips, named MOS Technology VIC-II (graphics) and MOS Technology SID (audio), was completed in November 1981.

A game console project was then initiated by Commodore that would use the new chips -- called the Ultimax or alternatively the Commodore MAX Machine, engineered by Yashi Terakura from Commodore Japan. This project was eventually cancelled after just a few machines were manufactured for the Japanese market.

At the same time Robert 'Bob' Russell (system programmer and architect on the VIC-20) and Robert Yannes (engineer of the SID) were critical of the current product line-up at Commodore, which was a continuation of the Commodore PET line aimed at business users. With the support of Al Charpentier (engineer of the VIC-II) and Charles Winterble (manager of MOS Technology), they proposed to Commodore CEO Jack Tramiel a true low-cost sequel to the VIC-20. Tramiel dictated that the machine should have 64 KiB of RAM. Although 64 KiB of DRAM cost over US Dollar100 at the time, he knew that DRAM prices were falling, and would soon drop to an acceptable level before full production was reached. In November, Tramiel set a deadline for the first weekend of January, to coincide with the 1982 Consumer Electronics Show.

The product was codenamed the VIC-40 as the successor to the popular VIC-20. The team that constructed it consisted of Robert Russell, Robert 'Bob' Yannes and David A. Ziembicki. The design, prototypes and some sample software was finished in time for the show, after the team had worked tirelessly over both Thanksgiving and Christmas weekends.

When the product was to be presented, the VIC-40 product was renamed C64 in order to fit into the current Commodore business products lineup which contained the P128 and the B256, both named by a letter and their respective memory size.

The C64 made an impressive debut, as recalled by Production Engineer David A. Ziembicki: 'All we saw at our booth were Atari people with their mouths dropping open, saying, 'How can you do that for Dollar595?'' The answer, as it turned out, was vertical integration; thanks to Commodore's ownership of MOS Technology's semiconductor fabrication facilities, each C64 had an estimated production cost of only Dollar135. However, cheaper manufacturing techniques resulted in manufacturing problems; Many of these early units had video problems causing a blurry effect that made alphanumeric characters difficult to read.

Winning the market war

The C64 faced a wide range of competing home computers at its introduction in August 1982. With an impressive price point coupled with the C64's advanced hardware, it quickly out-classed many of its competitors. In the United States the greatest competitors to the C64 were the Atari 8-bit 400 and 800, the IBM PC and the Apple II. The Atari 400 and 800 were very similar in hardware terms, but it was very expensive to build, which forced Atari to redesign their machine to be more cost effective. This resulted in the 600XL/800XL line and the transfer of their production to the Far East. The IBM PC and the now aging Apple II were no match for the C64's graphical and sound abilities, but they were very expandable with their internal expansion slots, a feature lacking in the 64.

All three machines had a standard memory configuration of 16 KiB, 48 KiB less RAM than the C64. At USDollar1,500, the IBM PC and Apple II were three times as expensive, while the Atari 800 cost a mere Dollar899. One key to the C64's success was Commodore's aggressive marketing tactics, and they were quick to exploit the relative price/performance divisions between its competitors with a series of television commercials after the C64's launch in late 1982.

Commodore sold the C64 not only through its network of authorized dealers, but also placed it on the shelves of department stores, discount stores, and toy stores. Since it had the ability to output composite video, the C64 did not require a specialized monitor, but could be plugged into a television set. This allowed it (like its predecessor, the VIC-20) to compete directly against video game consoles such as the Atari 2600.

Aggressive pricing of the C64 is considered to be a major catalyst in the video game crash of 1983. In 1983, Commodore offered a Dollar100 rebate in the United States on the purchase of a C64 upon receipt of any video game console or computer. To take advantage of the Dollar100 rebate, some mail-order dealers and retailers offered a Timex Sinclair 1000 for as little as Dollar10 with purchase of a C64 so the consumer could send the computer to Commodore, collect the rebate, and pocket the difference. Timex Corporation departed the marketplace within a year. The success of the VIC-20 and C64 also contributed significantly to the exit of Texas Instruments and other competitors from the field.

In 1984, Commodore released the Commodore Plus/4. The Plus/4 offered a higher-color display, a better implementation of BASIC (V3.5), and built-in software. However, Commodore committed what was perceived by critics and consumers as a major strategic error by making it incompatible with the C64. The Plus/4 lacked hardware sprite capability and had much poorer sound, thus seriously underperforming in two of the areas that had made the C64 a star.
In the United Kingdom, the primary competitors to the C64 were the British-built Sinclair ZX Spectrum and the Amstrad CPC 464. Released a few months ahead of the C64, and selling for almost half the price, the Spectrum quickly became the market leader. Commodore would have an uphill struggle against the Spectrum, it could no longer rely on undercutting the competition. The C64 debuted at Pound 399 in early 1983, while the Spectrum cost Pound 175. The C64 would later rival the Spectrum in popularity in the latter half of the 1980s, eventually outliving the Spectrum when it discontinued in December 1990.

Despite a few attempts by Commodore to discontinue the C64 in favour of other, higher priced machines, constant demand made its discontinuation a hard task. By 1988, Commodore were selling 1.5 million C64s worldwide. Although demand for the C64 dropped off in the US by 1990, it continued to be popular in the UK and other European countries. In the end, economics, not obsolescence sealed the C64's fate. In March 1994, at CeBIT in Hanover, Germany, Commodore announced that the C64 would be finally discontinued in 1995. Commodore claimed that the C64's disk drive was more expensive to manufacture than the C64 itself. Although Commodore had planned to discontinue the C64 by 1995, the company filed for bankruptcy a month later, in April 1994.


The C64 family

1982: Commodore releases the Commodore MAX Machine in Japan. It is called the Ultimax in the US, and VC-10 in Germany. The MAX was intended to be a game console with limited computing capability. It was discontinued months after its introduction, because of poor sales in Japan.

In 1984 Commodore released the SX-64, a portable version of the C64. The SX-64 has the distinction of being the first full-color portable computer. The base unit featured a 5 inch (127 mm) CRT and an integral 1541 floppy disk drive. The SX-64 did not have a cassette connector.
Commodore was determined to avoid the problems of the Plus/4, making sure that the eventual successors to the C64—the Commodore 128 and 128D computers (1985)—were as good as, and fully compatible with the original, as well as offering a host of improvements (such as a structured BASIC with graphics and sound commands, 80-column display capability, and full CP/M compatibility).

In 1986, Commodore released the Commodore 64C (C64C) computer, which was functionally identical to the original, but whose exterior design was remodelled in the sleeker style of the C128 and other contemporary design trends. In the United States, the C64C was often bundled with the third-party GEOS GUI-based operating system. The Commodore 1541 disk drive was also remodelled resulting in the 1541-II.

In 1990, the C64 was re-released in the form of a game console, called the C64 Games System (C64GS). A simple modification to the C64C's motherboard was made to orient the cartridge connector to a vertical position. This allowed cartridges to be inserted from above. A modified ROM replaced the BASIC interpreter with a boot screen to inform the user to insert a cartridge. The C64GS was another commercial failure for Commodore, and it was never released outside of Europe.

In 1990, an advanced successor to the C64, the Commodore 65 (also known as the 'C64DX'), was prototyped, but the project was cancelled by Commodore's chairman Irving Gould in 1991. The C65's specifications were very good for an 8-bit computer. For example, it could display 256 colours on screen, while OCS based Amigas could only display 64. Although no specific reason was given for the C65's cancellation, it would have competed in the marketplace with Commodore's lower end Amigas. The Amiga 600 was released in mid 1992, eventually taking the C65's place as the upgrade from the C64.


C64 clones

In the summer of 2004, after an absence from the marketplace of more than 10 years, PC manufacturer Tulip Computers BV (owners of the Commodore brand since 1997) announced the C64 Direct-to-TV (C64DTV), a joystick-based TV game based on the C64 with 30 games built into ROM. Designed by Jeri Ellsworth, a self-taught computer designer who had earlier designed the modern C-One C64 implementation, the C64DTV was similar in concept to other mini-consoles based on the Atari 2600 and Intellivision which had gained modest success earlier in the decade. The product was advertised on QVC in the United States for the 2004 holiday season. Some users have installed 1541 floppy disk drives, hard drives, second joysticks and keyboards to these units, which give the DTV devices nearly all of the capabilities of a full Commodore 64. The DTV hardware is also used in the mini-console/game Hummer, sold at Radio Shack mid-2005.

As of 2006, C64 enthusiasts still develop new hardware, including Ethernet cards, specially adapted hard disks and Flash Card interfaces.


Software

At the time of its introduction, the C64's graphics and sound capabilities were rivalled only by the Atari 8-bit family. This was at a time when most IBM PCs and compatibles had text-only graphics cards, green screen monitors, and sound consisting of squeaks and beeps from the built-in tiny, low-quality speaker.

Due to its advanced graphics and sound, the C64 is often credited with starting the computer subculture known as the demoscene (see Commodore 64 demos). The C64 lost its top position among demo coders when the 16-bit Atari ST and Commodore Amiga were released in 1985, however it still remained a very popular platform for demo coding up to the early 90s.

By the turn of the millennium, it was still being actively used as a demo machine, especially for music (its sound chip even being used in special sound cards for PCs, and the Elektron SidStation synthesizer). Unfortunately, the differences between PAL and NTSC C64s caused compatibility problems between U.S./Canadian C64s and those from most other countries. The vast majority of demos run only on PAL machines.


Hardware

Graphics and sound

The C64 used an 8-bit MOS Technology 6510 microprocessor. This was a close derivative of the 6502, with an added 6-bit internal I/O port that in the C64 is used for two purposes: to bank-switch the machine's ROM in and out of the processor's address space, and to operate the datasette tape recorder.

The C64 had 64 kbytes of RAM, of which 38 KiB were available to built-in Commodore BASIC 2.0.

The graphics chip, VIC-II, featured 16 colors, eight hardware sprites, scrolling capabilities, and two bitmap graphics modes. The standard text mode featured 40 columns, like most Commodore PET models; the built in font was not standard ASCII but PETSCII, an extended form of ASCII-1963. Computer/video game and demo programmers quickly learned how to exploit undocumented or esoteric features of the VIC-II to gain additional capabilities, such as making more than 8 sprites appear on the screen (up to 128 in one case) or displaying additional colors beyond the 'factory' 16.

The sound chip, SID, had three channels, each with its own ADSR envelope generator, and with several different waveforms, ring modulation and filter capabilities. It too, was very advanced for its time. It was designed by Bob Yannes, who would later co-found synthesizer company Ensoniq. Yannes criticized other contemporary computer sound chips as 'primitive, obviously (...) designed by people who knew nothing about music.' Often the game music became a hit of its own among C64 users. Well-known composers and programmers of game music on the C64 were Rob Hubbard, David Whittaker, Chris Hülsbeck, Ben Daglish, Martin Galway and David Dunn among many others. Due to the chip's limitation to three channels, chords were played as arpeggios typically, coining the C64's characteristic lively sound.

There are two versions of the SID chip. The first version was the MOS Technology 6581, which is to be found in all of the original 'breadbox' C64s, and early versions of the C64C and the Commodore 128. It was later replaced with the MOS Technology 8580 in 1987. The sound quality was a little more crisp on the 6581 and many Commodore 64 fans still prefer its sound. The main difference between the 6581 and the 8580 was the voltage supply: the 6581 uses a 12 volt supply, while the 8580 required only 9 volts. A voltage modification can be made to use a 6581 in a C64C board (which uses 9V).

The SID chip has a distinctive sound which retained a following of devotees. In 1999, Swedish company Elektron produced a SidStation synth module, built around the SID chip, using remaining stocks of the chip. Several bands use these devices in their music.


Hardware revisions

Cost reduction was the driving force for hardware revisions to the C64's motherboard. Reducing manufacturing costs was vitally important to Commodore's survival during the price war and leaner years of the 16-bit era. The C64's original (NMOS based) motherboard would go through two major redesigns, (and numerous sub-revisions) exchanging positions of the VIC-II, SID and PLA chips. Initially, a large proportion of the cost was lowered by reducing the number of discrete components used, such as diodes and resistors.

The VIC-II was manufactured with 5 micrometre NMOS technology, clocked at 8 MHz. At such a high clock rate, it generated a lot of heat, forcing MOS Technology to use a ceramic DIL package (called a 'CERDIP'). The ceramic package was more expensive, but it dissipated heat more effectively than plastic.

After a redesign in 1983, the VIC-II was encased in a plastic DIL package, which reduced costs substantially, but it did not eliminate the heat problem. Without a ceramic package, the VIC-II required the use of a heatsink. To avoid extra cost, the metal RF shielding doubled as the heatsink for the VIC, although not all units shipped with this type of shielding. Most C64s in Europe shipped with a cardboard RF shield, coated with a layer of metal foil. The effectiveness of the cardboard was highly questionable, and worse still it acted as an insulator, blocking airflow which trapped heat generated by the SID, VIC and PLA chips.

The SID was manufactured using NMOS at 7 and in some areas 6 micrometres. The prototype SID and some very early production models featured a ceramic DIL package, but unlike the VIC-II, these are extremely rare as the SID was encased in plastic when production started in early 1982.

In 1986 Commodore released the last revision to the 'classic' C64 motherboard. It was otherwise identical to the 1984 design, except that it now used two 64 kbit x4 DRAM chips rather than the original eight 64 kbit x1.

After the release of the C64C, MOS Technology began to reconfigure the C64's chipset to use HMOS technology. The main benefit of using HMOS was that it required less voltage to drive the IC, which consequently generates less heat. This enhanced the overall reliability of the SID and VIC-II. The new chipset was re-numbered to 85xx in order to reflect the change to HMOS.
In 1987 Commodore released C64Cs with a totally redesigned motherboard commonly known as a 'short board'. The new board used the new HMOS chipset, featuring new 64-pin PLA chip. The new 'SuperPLA' as it was dubbed, integrated many discrete components and TTL chips. The 2114 color RAM was integrated into the last revision of the PLA.

The C64 used an external power supply. While this saved valuable space within the computer's case, the supply itself was barely adequate for the C64's power requirements. Commodore's plastic power bricks would typically break from overheating. Some users purchased heavier-duty, better-cooled, third-party power supplies. The C64's disk drives also came with their own external power supplies.

Later in the Commodore's lifetime, third-party power supplies became increasingly important when used in conjunction with RAM expansions or Creative Micro Designs' peripherals. Of particular note, a C64 coupled with a RAM expansion or CMD SuperCPU required more power than the original Commodore power supply could provide. A modern PC power unit can be modified to power a C64 and its disk drives.


Specifications

Internal hardware

Microprocessor CPU:
* MOS Technology 6510/8500 (the 6510/8500 being a modified 6502 with an integrated 6-bit I/O port)
* Clock speed: 1.023 MHz (NTSC) or 0.985 MHz (PAL)

Video: MOS Technology VIC-II 6567/8567 (NTSC), 6569/8569 (PAL)
* 16 colors
* Text mode: 40x25 characters; 256 user-defined chars (8x8 pixels, or 4x8 in multicolor mode); 4-bit color RAM defines foreground color
* Bitmap modes: 320x200 (2 colors in each 8x8 block), 160x200 (3 colors plus background in each 4x8 block)
* 8 hardware sprites of 24x21 pixels (12x21 in multicolor mode)
* Smooth scrolling, raster interrupts

Sound: MOS Technology 6581/8580 SID
* 3-channel synthesizer with programmable ADSR envelope
* 8 octaves
* 4 waveforms: triangle, sawtooth, variable pulse, noise
* Oscillator synchronization, ring modulation
* Programmable filter: high pass, low pass, band pass, notch filter

RAM:
* 64 KiB (65,536 bytes), of which 38 KiB minus 1 byte (38,911 bytes) were available for BASIC programs
* 512 bytes color RAM
* Expandable to 320 KiB with Commodore 1764 256 KiB RAM Expansion Unit (REU); although only 64 KiB directly accessible; REU mostly intended for GEOS. REUs of 128 KiB and 512 KiB, originally designed for the C128, were also available, but required the user to buy a stronger power supply from some third party supplier; with the 1764 this was included. Creative Micro Designs also produced a 2 MB REU for the C64 and C128, called the 1750 XL. The technology actually supported up to 16 MB, but 2 MB was the biggest one officially made. Expansions of up to 16 MB were also possible via the CMD SuperCPU.

ROM:
* 20 KiB (9 KiB BASIC 2.0; 7 KiB KERNAL; 4 KiB character generator, providing two 2 KiB character sets)

I/O ports and power supply:
* I/O ports:
* 8-pin DIN plug containing composite video output, separate Y/C outputs, and sound input/output. (Some early C64 units utilized a 5-pin DIN connector that omitted the Y/C output.)
* Integrated RF modulator antenna output via a RCA connector
* 2 x screwless DE9M game controller ports (compatible with Atari 2600 controllers), each supporting five digital inputs and two analog inputs. Available peripherals included digital joysticks, analog paddles, a light pen, the Commodore 1351 mouse, and the unique KoalaPad.
* Cartridge expansion slot (slot for edge connector with 6510 CPU address/data bus lines and control signals, as well as GND and voltage pins; used for program modules and memory expansions, among others)
* PET-type Datassette 300 baud tape interface (edge connector with cassette motor/read/write/sense signals and GND and +5 V pins; the motor pin is powered to directly supply the motor)
* User port (edge connector with TTL-level RS-232 signals, for modems, etc; and byte-parallel signals which can be used to drive third-party parallel printers, among other things; with 17 logic signals, 7 GND and voltage pins, including 9V AC voltage)
* Serial bus (serial version of IEEE-488, 6-pin DIN plug) for CBM printers and disk drives
* Power supply:
* 5V DC and 9V AC from an external 'power brick', attached to a 7-pin female DIN-connector on the computer. The C64's original power brick was under-powered, and users would often replace it with a third party solution, particularly if they had power-hungry peripherals attached to their machines.


Notes on C64 Software

* On address DollarFFF6-DollarFFF9 (65526-9) in the C64 KERNAL, immediately before the hard-coded jump vectors for the processor, is letter sequence 'RRBY'. These are the initials of Robert Russell and Bob Yannes, the two main engineers that created the C64.
* The Commodore 64's BASIC V2, the programming language which came built-in with the computer, can be crashed by executing PRINT''+-[x] (where x is any integer), or by attempting to create a BASIC program with an initial line number near 350800.
* Due to a quirk in the C64's BASIC operating system, an Easter egg or screensaver of sorts may be activated by pressing the RUN/STOP and RESTORE keys in unison, then entering POKE781,96:SYS58251 on the subsequently cleared screen.
* There is a way to hide lines of code written in the BASIC Language stored in local memory. It involved using the 'heart' symbol.
* Entering the character shift-L (which looks like an L-shaped border corner) into the program code will cause a syntax error when that line is LISTed. This is a simple way to prevent arbitrary listing of the program code.


Infos from Wikipedia

Commodore 65

The CAB 65 was compatible with the Apple II.

Commodore Amiga

The Amiga is a family of personal computers originally developed by Amiga Corporation. Development on the Amiga began in 1982 with Jay Miner as the principal hardware designer. Commodore International bought Amiga Corporation and introduced the machine to the market in 1985. The name Amiga was chosen by the developers specifically from the Spanish and Portuguese word for a female friend, and because it occurred before Apple and Atari alphabetically.

Based on the Motorola 68k series of microprocessors, the machine sported a custom chipset with advanced graphics and sound capabilities, and a pre-emptive multitasking operating system (now known as AmigaOS). While the M68k was a 32-bit processor, the version originally used in the Amiga, the 68000, had a 16-bit external data bus, and the original machine (along with its contemporary, the Atari ST) was generally referred to in the press as a 16-bit computer; later models sported fully 32-bit designs. The Amiga provided a significant upgrade from 8-bit computers such as the Commodore 64, and the Amiga quickly grew in popularity among computer enthusiasts, especially in Europe, and sold approximately 6 million units.

It also found a prominent role in the desktop video / video production and show control business, and was a less-expensive alternative to the Apple Macintosh and IBM-PC. The Amiga was most commercially successful as a home computer, although early Commodore advertisements attempted to place the Amiga into several different markets at the same time.

Since the demise of Commodore, various groups have marketed successors to the original Amiga line. Eyetech sold Amiga hardware under the AmigaOne brand from 2002 till 2005.


History

The Amiga was originally designed by a small company called Amiga Corporation, and initially intended to be a next generation video game machine, but was later redesigned into a general purpose computer. Before the machine was released into the market the company was purchased by Commodore. The first model, later known as the Amiga 1000, was released in 1985 as a successor to the Commodore 64 and as a rival to the Atari ST. Commodore later released several new Amiga models, both for low-end gaming use and high-end productivity use. Throughout the 1980s, the Amiga's combination of hardware and operating system software offered great value, but by the mid-nineties other platforms, most of all the PC, reduced or eliminated this advantage.

In 1994, Commodore filed for bankruptcy and its assets were purchased by Escom, a German PC manufacturer, who created the subsidiary company Amiga Technologies. They re-released the A1200 and A4000T, and introduced a new 68060 version of the A4000T.

However, Escom in turn went bankrupt in 1997. The Amiga brand was then sold to another PC manufacturer, Gateway 2000, which had announced grand plans for it. However, in 2000, Gateway sold the Amiga brand.

The current owner of the trademark, Amiga, Inc., has licensed the rights to make hardware using the Amiga brand to a UK computer vendor, Eyetech Group, Ltd, which was founded by some former UK employees of Commodore International. They are currently selling the AmigaOne via an international dealer network. The AmigaOne is a PowerPC computer designed to run the latest version of AmigaOS, which was itself licensed to a Belgian-German company, Hyperion Entertainment.


Hardware

At its core, the Amiga featured custom designed coprocessors, useful for handling tasks such as audio, video, encoding and animation. This freed up the Amiga's central processor for other tasks (given that the coprocessors could keep up with the central processor's demands) and gave the Amiga an edge on its competitors in many situations.

The platform also introduced other innovations. For example, the Amiga CDTV was the first computer to feature a CD-ROM drive as standard, as well as being one of the earlier computers to no longer include a floppy drive in the standard configuration. The Amiga was also one of the first computers for which inexpensive sound sampling and video digitization accessories were available.

Although it was once regarded as 'unemulatable,' since around 2000, hardware has developed to a point where many different platforms have Amiga emulation programs available that reproduce the Amiga's hardware functions in software. This allows users to run Amiga software without the need for an actual Amiga computer.


Central processing unit

PowerPC processor.All Commodore Amiga models make use of Motorola Central Processing Units (CPUs) based on the Motorola 68k architecture. In desktop-style Amiga models, the CPU was fitted on a daughterboard (except the A2000) called a CPU card. Low-cost Amiga models came with CPUs either socketed or soldered onto the motherboard. On all Amiga models the CPU could be upgraded through an expansion card or direct CPU replacement. CPU cards were provided by both Commodore and third-party manufacturers. These cards often came with on-board memory slots and hard drive interfaces, alleviating those tasks from the base Amiga.

The Amiga was not limited to solely the 68k CPU architecture; it was also possible to install a PowerPC coprocessor that could be used by PowerPC-aware software and libraries, and later the AmigaOne used a PowerPC CPU instead of a 68k CPU.


Custom chipset

The Amiga's custom chipset, as the name implies, consists of a number of chips.

There are three generations of chipsets used in the various Amiga models. The first was the OCS, followed by the ECS and finally the AGA. What all these chipsets have in common is that they handle raster graphics, digital audio and communication between various peripherals (e.g., CPU, memory and floppy disks) in the Amiga.


Graphics

All Amiga systems can display full-screen animated graphics with 32, 64 (EHB Mode) or 4096 colors (HAM Mode). Models with the AGA chipset (A1200 and A4000) also have 128, 256 and 262,144 color modes and a palette expanded from 4096 to 16.8 million colors. The Amiga chipset could genlock — adjust its own screen refresh timing to match an NTSC or PAL video signal. When combined with setting transparency, this allowed an Amiga to overlay an external video source with graphics. This ability made the Amiga popular for many applications, and provided the ability to do character generation and CGI effects far more cheaply than earlier systems. Some frequent users of this ability included wedding videographers, TV stations and their weather forecasting divisions (for weather graphics and radar), advertising channels, music video production, and 'desktop video'. The NewTek Video Toaster was made possible by the genlock ability of the Amiga.


Sound

The sound chip, named Paula, supports four sound channels (two for the left speaker and two for the right) with 8-bit resolution for each channel and a 6-bit volume control per channel. The analog output is connected to a low-pass filter, which filters out high-frequency aliases when the Amiga is using a lower sampling rate (see Nyquist limit). The brightness of the Amiga's power LED is used to indicate the status of the Amiga's low-pass filter. The filter is active when the LED is at normal brightness, and deactivated when dimmed. Older Amiga 500's simply turned off the power LED. On Amiga 1000, the power LED had no relation to the filter's status, you had to manually solder a wire between pins on the sound chip to disable the filter. Paula can read directly from the system's RAM, using direct memory access (DMA), making sound playback without CPU intervention possible.

Although the hardware is limited to four separate sound channels, software such as OctaMED uses software mixing to allow eight or more virtual channels, and it was possible for software to mix two hardware channels to achieve a single 14-bit resolution channel by playing with the volumes of the channels in such a way that one of the source channels contributes the most significant bits and the other the least ones.

It is also possible to use interrupts to control the sound chip and get 14 bits for all four channels. It should also be possible to mix the two channels on each side and get 15-bit sound. Because of the interrupts, this will require a lot of CPU time.

The quality of the Amiga's sound output, and the fact that the hardware is ubiquitous and easily addressed by software, were standout features of Amiga hardware unavailable on PC platforms for years. Third-party sound cards exist that provide DSP functions, multi-track direct-to-disk recording, multiple hardware sound channels and 16-bit and beyond resolutions. A retargetable sound API called AHI was developed allowing these cards to be used transparently by the OS and software.


ROM

The classic Amiga Operating System consisted of Kickstart (including System API) and Workbench. In the Amiga 1000 model, Kickstart was first loaded from a floppy disk, followed by Workbench, or other bootable disk. Later models held Kickstart (and system API) on a ROM, improving start-up times. Models could be upgraded by changing the ROM.

The early ROMs were generally known as 'Kickstart' and started with version 1.0 (A1000 floppy) and ending with Kickstart 3.1. There are hardware and software packages that can 'shadow' Kickstart into memory. This resulted in faster operation for functions dependent on the ROM, at the cost of system memory to store the ROM data.


Three finger salute

The Amiga's three-finger salute (CTRL plus the two 'Amiga' keys), which reboots the system (but does not erase or reload the Kickstart software), is actually implemented in hardware common to the Apple II (CTRL-Open Apple-Reset), but unlike the IBM PC (whose Ctrl-Alt-Del is implemented in software). Another kind of three-finger salute (CTRL plus the two 'Alt' keys) was introduced with AmigaOS 4.0 which resets the machine entirely, forcing a reload of the Kickstart.


Third party hardware

Many expansion boards were produced for Amiga computers to improve the performance and capability of the hardware, such as memory expansions, SCSI controllers, CPU boards, and graphics boards. Other upgrades included genlocks, ethernet cards, modems, sound cards and samplers, video digitizers, USB cards, extra serial ports, and IDE controllers.

The most popular upgrades were memory, SCSI controllers and CPU accelerator cards. These were sometimes combined into the one device, particularly on big-box Amigas like the A2000, A3000 and A4000.

Early CPU accelerator cards featured full 32-bit CPUs of the 68000 family such as the Motorola 68020 and Motorola 68030, almost always with 32-bit memory and usually with FPUs and MMUs or the facility to add them. Later designs featured the Motorola 68040 and Motorola 68060. Both CPUs featured integrated FPUs and MMUs. Many CPU accelerator cards also had integrated SCSI controllers.

Phase5 designed the PowerUp boards (BlizzardPPC and CyberstormPPC) featuring both a 68k (a 68040 or 68060) and a PPC (603 or 604) CPU, which are able to run the two CPUs at the same time (and share the system memory). The PPC CPU on PowerUp boards is usually used as a coprocessor for heavy computations (a powerful CPU is needed to run for example MAME, but even decoding JPEG pictures and MP3 audio was considered heavy computation in those years). It is also possible to ignore the 68k CPU and run Linux on the PPC (project Linux APUS), but a PPC-native Amiga OS was not available when the PPC boards first appeared.

24-bit graphics cards and video cards were also available. Graphics cards are designed primarily for 2D artwork production, workstation use, and later, gaming. Video cards are designed for inputting and outputting video signals, and processing and manipulating video.

Perhaps the most famous video card in the North American market was the NewTek Video Toaster. This was a powerful video effects board which turned the Amiga into an affordable video processing computer which found its way into many professional video environments. Due to its NTSC-only design it did not find a market in countries that used the PAL standard, such as in Europe. In PAL countries the OpalVision card was popular, although less featured and supported than the Video Toaster. Low-cost time base correctors (TBCs) specifically designed to work with the Toaster quickly came to market, most of which were designed as standard Amiga bus cards.

Various manufacturers started producing PCI busboards for the A1200 and A4000, allowing standard Amiga computers to use PCI cards such as Voodoo graphic cards, Sound Blaster sound cards, 10/100 ethernet cards, and TV tuner cards.

PowerPC upgrades with Wide SCSI controllers, PCI busboards with ethernet, sound and 3D graphics cards, and tower cases allowed the A1200 and A4000 to survive well into the late nineties.

Expansion boards were made by Richmond Sound Design that allowed their show control and sound design software to communicate with their custom hardware frames either by ribbon cable or fiber optic cable for long distances, allowing the Amiga to control up to eight million digitally controlled external audio, lighting, automation, relay and voltage control channels spread around a large theme park, for example. See Amiga software for more information on these applications.


Models and variants
Main article: Amiga models and variants

The Amiga 500 (1987) was the most popular variant of the Amiga.The 'classic Amiga' models were produced from 1985 to 1996. They are, in order of appearance: 1000, 2000, 500, 1500, 2500, 3000, 3000UX, 500+, 3000T, CDTV, 600, 4000, 1200, CD32, and 4000T. The PowerPC based AmigaOne was later produced from 2002 to 2005. Some companies have also released Amiga clones.

The Amiga 500 was Commodore's best-selling Amiga model. Early units, at least, had the words 'B52/ROCK LOBSTER' silk-screen printed onto their printed circuit board, a reference to the popular song by the rock band the B-52's. Commodore's two subsequent console style models also carried a reference to the same band on their motherboards - the Amiga 600 had 'JUNE BUG' and the Amiga 1200 had 'CHANNEL Z'.

The Amiga 500+ was the shortest lived model, replacing the Amiga 500 and lasting only six months until it was phased out and replaced by the Amiga 600.

Commodore released three significant upgrades: the Amiga 2000 in 1987, the Amiga 3000 in 1990, and the Amiga 4000 in 1992. These upgrades improved the platform's graphical abilities, allowing for more colors and different display modes, and added expansion slots and ports. The best selling models, however, were the much cheaper but still versatile console models - the Amiga 500 (1987) and the Amiga 1200 (1992).

In 2006, PC World rated the Amiga 1000 as the seventh greatest PC of all time, stating 'Years ahead of its time, the Amiga was the world's first multimedia, multitasking personal computer'.


AmigaOS 4 systems
AmigaOS 4 is designed for PowerPC Amiga systems and currently runs on both Amigas equipped with CyberstormPPC or BlizzardPPC accelerator boards, and on the PPC Teron series based AmigaOne computers built by Eyetech under license by Amiga Inc. AmigaOS 4.0 had been available only in developer pre-releases for numerous years until the final update was 'released' in December 2006. Due to the nature of some provisions of the contract between Amiga Inc. and Hyperion Entertainment the Belgian-German firm which is developing the OS, the commercial AmigaOS had only been available licensed to buyers of AmigaOne motherboards.

AmigaOS 4.0 for Classic Amigas equipped with PPC (Cyberstorm PPC or BlizzardPPC) accelerator boards was released commercially in November 2007, prior to this it was available only to developers and beta-testers.

There have been no major changes or feature enhancements to Amiga OS 4.0 since December, 2006, and no new hardware released since the AmigaOne, despite rumors of several PowerPC-based motherboards.


Amiga hardware clones
Long-time Amiga developer MacroSystems entered the Amiga-clone market with their DraCo nonlinear video edit system. It appeared in two versions, initially a tower model and later a cube. DraCo expanded upon and combined a number of earlier expansion cards developed for Amiga (VLabMotion, Toccata, WarpEngine, RetinaIII) into a true Amiga-clone powered by Motorola's 68060 processor. The DraCo can run AmigaOS 3.1 up through AmigaOS 3.9. It is the only Amiga-based system to support FireWire for video I/O. DraCo also offers an Amiga-compatible ZORRO-II expansion bus and introduced a faster custom DraCoBus, capable of 30 MB/sec transfer rates (faster than Commodore's ZORRO-III). The technology was later used in the Casablanca system, a set-top-box also designed for non-linear video editing.

In 1998, Index Information released the Access, an Amiga-clone similar to the A1200, but on a motherboard which could fit into a standard 5 .1/4' drive bay. It featured either a 68020 or 68030 CPU, with a redesigned AGA chipset, and ran AmigaOS 3.1.

In 2006, two new Amiga-clones were announced. The Minimig is a personal project of Dutch engineer Dennis van Weeren. Minimig replicates the Amiga OCS custom chipset inside an FPGA. The original model was built on a Xilinx Spartan 3 development board, but now a dedicated board has been demonstrated. The design for Minimig was released as Open Source on July 25, 2007. In December, 2007, an Italian company Acube Systems announced plans to commercially produce the original Minimig. In February 2008 Acube began selling Minimig boards.

Individual Computers has announced development of the Clone-A system. As of mid 2007 it has been shown in its development form, with FPGA-based boards replacing the custom chips in an Amiga 500.


Operating systems

AmigaOS

Amiga OS 3.9At the time of release AmigaOS put an OS that was well ahead of its time into the hands of the average consumer. It was the first commercially available consumer operating system for personal computers to implement preemptive multitasking . Other features included combining a graphical user interface with a command-line interface, allowing long filenames permitting whitespace and not requiring a file extension and the use of information files associated with other files to store icons, launch and other desktop data.

John C. Dvorak stated in 1996 that AmigaOS 'remains one of the great operating systems of the past 20 years, incorporating a small kernel and tremendous multitasking capabilities the likes of which have only recently been developed in OS/2 and Windows NT. The biggest difference is that the AmigaOS could operate fully and multitask in as little as 250 K of address space.'

Like other operating systems of the time, the OS lacked memory protection. This was necessary also because the 68000 CPU of the first Amiga computers did not include a memory management unit, and because there was no way of enforcing use of flags indicating memory to be shared. Although it eased interapplication communication (programs could communicate by simply passing a pointer back and forth), the lack of memory protection made the Amiga OS more vulnerable to crashes from badly behaving programs, and fundamentally incapable of enforcing any form of security model since any program had full access to the system. Later this memory protection feature was implemented in Amiga OS 4.

The problem was somewhat exacerbated by Commodore's initial decision to release documentation relating not only to the OS's underlying software routines, but also to the hardware itself, enabling intrepid programmers who cut their teeth on the Commodore 64 to POKE the hardware directly, as was done on the older platform. While the decision to release the documentation was a popular one and allowed the creation of fast, sophisticated sound and graphics routines in games and demos, it also contributed to system instability as some programmers lacked the expertise to program at this level. For this reason, when the new AGA chipset was released, Commodore declined to release documentation for it, forcing most programmers to adopt the approved software routines.

Following Commodore's bankruptcy, two main clones of AmigaOS were developed: MorphOS, which runs on Amiga and Pegasos machines, and the free software AROS project.


Unix and Unix-like systems

Commodore-Amiga produced Amiga Unix, informally known as Amix, based on AT&T SVR4. It supported the Amiga 2500 and Amiga 3000 and was included with the Amiga 3000UX. Among other unusual features of Amix was a hardware-accelerated windowing system which could scroll windows without copying data. Amix was not supported on the later Amiga systems based on 68040 or 68060 processors.

Other, still maintained, operating systems are available for the classic Amiga platform, including Linux and NetBSD. Both require a CPU with MMU such as the 68020 with 68851 or full versions of the 68030, 68040 or 68060. There is also a version of Linux for Amigas with PowerPC accelerator cards. Debian and Yellow Dog Linux can run on the AmigaOne.

There is an official, older version of OpenBSD. The last Amiga release is 3.2. Minix 1.5.10 also runs on Amiga.


Emulating other systems

The Amiga is able to emulate other computer platforms ranging from many 8-bit systems such as the ZX Spectrum, Commodore 64, Nintendo Game Boy, Nintendo Entertainment System, Apple II and the TRS-80, to platforms such as the IBM PC and Apple Macintosh. MAME (the arcade machine emulator) is also available for Amiga systems with PPC accelerator card upgrades.


Amiga software

The Amiga was a primary target for productivity and game development during the late 1980s and early 1990s. Software was often developed for the Amiga and the Atari ST simultaneously, since the ST shared a similar architecture.

Much of the freely available software was available on Aminet. Until around 1996, Aminet was the largest public archive of software for any platform.


Bootblock

If an Amiga 500 is rebooted or powered without a floppy this screen is displayed. The displayed OS is Kickstart 34.5 (AmigaOS 1.3), included in the Amiga 500 ROM.When an Amiga is reset, the Kickstart code selects a boot device (floppy or hard drive), loads the first two sectors of the disk or partition (the bootblock), and passes control to it. Normally this code passes control back to the OS, continuing to boot from the device or partition it was loaded from. The first production Amiga, the Amiga 1000, needed to load Kickstart from floppy disk into 256 kilobytes of RAM reserved for this purpose, but subsequent Amigas held Kickstart in ROM. Some games and demos for the A1000 (notably Dragon's Lair) provided an alternative code-base in order to use the extra 256 kilobytes of RAM for data.

A floppy disk or hard drive partition bootblock normally contains code to load the 'dos.library' (AmigaDOS) and then exit to it, invoking the GUI. Any such disk, no matter what the other contents of the disk, was referred to as a 'Boot disk', 'bootable disk' or 'Workbench disk'. (A bootblock could be added to a disk by use of the 'install' command.) Some entertainment software contains custom bootblocks. The game or demo then takes control of memory and resources to suit itself, effectively disabling AmigaOS and the Amiga GUI.

The bootblock became an obvious target for virus writers. Some games or demos that used a custom bootblock would not work if infected with a bootblock virus, as the virus's code replaced the original. The first such virus was the SCA virus. Anti-virus attempts included custom bootblocks. These amended bootblock advertised the presence of the virus checker while checking the system for tell-tale signs of memory resident viruses and then passed control back to the system. Unfortunately these could not be used on disks that already relied on a custom bootblock, but did alert users of potential trouble. Several of them also replicated themselves across other disks, becoming little more than viruses in their own right.


Boing Ball

The Boing Ball has been synonymous with Amiga since its public release in 1985. It has been a popular theme in computer demo effects since the 1950s, when a bouncing ball demo was released for Whirlwind computers. Commodore released a bouncing ball demo at the 1978 Consumer Electronics Show, to illustrate the capabilities of the VIC chip. A similar theme was used to demonstrate the capabilities of the Amiga computer at the 1984 Consumer Electronics Show. It was a real-time animation showing a red-and-white balloon bouncing forth and back off the edges of the screen, as a deep 'boing!' sound played on each impact. Since then, the Boing Ball became one of the most well-known symbols for Amiga and compatible computers. Within the context of this tradition of bouncing ball demos at the Consumer Electronics Show, CBS Electronics also showed a Bouncing Ball demo for the Atari VCS/2600, with a spinning and bouncing ball, at the same event.

The 1984 Boing Ball demo was one of the very first demos shown on the Amiga. It was specifically designed to take advantage of the Amiga's custom graphics and sound hardware, achieving a level of speed and smoothness not previously seen on a home computer. This demo operated in an Intuition Screen, allowing the higher resolution Amiga Workbench screen to be dragged down to make the Boing Ball visible from behind, bouncing up above the Workbench while the Workbench remained fully active. Since the Boing Ball used almost no CPU time, this made a particularly impressive demonstration of multitasking at the time.

Despite its popularity in the Amiga community, the Boing Ball itself was never officially adopted as a trademark by Commodore. The official Amiga trademark was a rainbow-colored double checkmark. After the bankruptcy of Commodore, the Boing Ball remained in use as one of the symbols for Amiga-related systems on hundreds of web sites and products by different companies and individuals.

The demo was once ported to the Atari 2600 under the title Boing. The porter impressed himself so much that he added a little Easter Egg, which he referred to as lame (When you hold down the game reset switch, the checkered ball turns into a message that says HAPPY XMAS 1999!-----FROM ROB KUDLA and Jingle Bells starts playing. You also won't hear the bounce sound effect. Releasing the switch stops the music, turns the message back into the checkered ball, and the boing sound effect is played again when the ball bounces).


Amiga community

When Commodore went bankrupt in 1994, there was still a very active Amiga community, and it continued to support the platform long after mainstream commercial vendors abandoned it. The most popular Amiga magazine, Amiga Format, continued to publish editions until 2000, some six years after Commodore filed for bankruptcy. Another magazine, Amiga Active, was launched in 1999 and was published until 2001. Interest in the platform is high enough to sustain a specialist column in the UK weekly magazine Micro Mart.

As of mid-2006, there was enough demand for Amiga expansion hardware to keep some small scale manufacturers in business.

Infos from: Wikipedia

Commodore Amiga 1000

The inventor of the Amiga 1000 was Jay Miner, who created the Atari 800 many years before. He wanted to make the most powerful computer ever, then he joined a small Californian company called Amiga. He used the principle of the three coprocessors (again) to help the main processor.
At the beginning, the Amiga had only 64 kilobytes of RAM! The original "Amiga" called the Lorraine was meant to be a game machine with some computer capabilities.
Atari initially invested the money in the Amiga Corp. to do the R&D on the Amiga computer line. Naturally, when the design was finished, Amiga Corp. gave Atari the choice to purchase the technology. Atari passed in favor of their own project. Amiga Corp. then offered the technology to Commodore, Inc., who were quite pleased to purchase it, seeing that their own 16-bit computer was so far from reaching the shelf.
After the loss of a major legal battle for control of the Amiga chip set design, Atari launched the ST series (Sixteen-Thirty-two) as a competitor for the upcoming Amiga.
The operating system (AmigaDOS) was done by MetaComCo, a British company who specialized in the 68000 processor (they also made languages for the Sinclair QL). It is a fully multitasking system which looks like UNIX with a graphical user interface.
It was the very first personal computer with great graphics and sound capabilities with a GUI environment.
The Amiga BASIC was written by Microsoft (like most other versions of BASIC), but the first models were shipped with a non-Microsoft BASIC called ABasiC.
The Amiga 1000 was to lose popularity one year later with the creation of its two main successors: the Amiga 500 and the Amiga 2000.
There were two versions of the Amiga 1000. The first one sold only in the USA, had a NTSC display and no EHB video mode. Later versions would have this built in. The second one had a PAL display, the enhanced video modes (EHB) and was built in Germany.
The official name for the A1000 was the Commodore Amiga. It was only when the A2000 was launched that they officially began to refer to the machine by its model number.

Commodore Amiga 1200

In October 1992 the Amiga 1200 was launched. This machine took the A500 approach to computing with the "distinct" Commodore case, but including the AGA chipset present in the A4000, 2 MB RAM, and the PCMCIA slot from the A600.
At the price of ?399 it sold like hot cakes and is seen as one of the best Amigas to date. It appears to have been rushed to launch for the Christmas period with manuals claiming to give you the opportunity to upgrade from 1mb to 2mb chip ram with FPU. It is, however, a darn fine machine that can be easily upgraded for most of your needs.
After Escom bought the Amiga during 1995 it was relaunched to mass outrage. The machine still cost ?399, ?150 more than it had done a year previously and was not enhanced in any dramatic fashion. It was released in two versions- the Amiga Magic pack and the Amiga Surfer bundle. Unfortunately, the former was never released due to Escoms financial situation. The Escom Amigas were also struck by incompatibility problems due to a different disk drive being used, it was actually a PC high-density drive mechanism that had been altered to allow compatibility with the Amiga file system. Unfortunately, some games that hit the hardware directly would not run. A circuit upgrade was released free of charge that allowed users to fix the drive problem.
Source: Amiga Interactive Guide

Commodore Amiga 3000

The Commodore Amiga 3000 is the successor of the Amiga 2500 (itself a successor of the Amiga 2000). It was replaced three years later with the Amiga 4000.
Amiga Interactive Guide description :
The A3000 is a powerhouse in comparison to previous Amiga, it was sold as a high-end graphics workstation. For a time it was used by W Industries as the basis of their highly acclaimed Virtuality machines. At the heart of the A3000 was the powerful 68030 (described in ST/Amiga Format as a 'as a mainframe on a chip'). In addition the A3000 was the first Amiga to feature the new Kickstart 2 upgrade and Zorro III slots.
To emphasis the A3000s capabilities as a high-end workstation, two operating systems were included:
The first was the newly released Kickstart/Workbench 2. This was unusual by the fact that Kickstart was stored on the hard disk rather than in ROM. This was similar to the A1000 that required Kickstart to be loaded from floppy disk before anything else could be done.
The second OS to be included with the A3000 was the Unix System (SVR4) V operating system. This allowed the use of the Unix graphical interface, X Windows and Open Look. It also came with standard networking capabilities (probably a first for Commodore), such as TCP/IP, NFS and RFS for networking between different operating systems. In a bizarre twist, the Unix OS was sold on a magnetic tape rather than floppy disk.

Three Amiga 3000 models were produced : 3000, 3000UX, and 3000T.
The 3000 was the desktop model (pictured here) which shipped with flippable 1.3 or 2.0 AmigaOS Roms. The Amiga 3000T, released in 1991, was a tower system with built-in speaker, 32Mb RAM, high-resolution mouse, 100 Mb hard-drive, a lot of Zorro II slots, a variety of drive bays, and a 25Mhz 68030 with a 68882 math coprocessor. The 3000UX shipped with "AMIX", Commodore's System-5 derived UNIX which was very nice and came with X-windows. It was Commodore's only serious attempt to get into the UNIX workstation market, and a noble effort that unfortunately failed utterly.
Notice there are some rare versions of the Amiga 3000: the 3000/16 (the speed is only 16 MHz) and the Amiga 3000+ which uses an AGA video chip and a DSP. The 3000+ was a prototype only. A few units are known to exist, but they are not supported. The DSP was able to function as a software modem in some configurations, which was extremely cool.

Commodore Amiga 4000

In 1992 Commodore launched the most advanced Amiga yet. The A4000 used the AGA chipset to allow it to show 256,000 colours on screen from a palette of 16.8 million, as well as the new Workbench 3 that introduced the concept of among other things, datatypes. The Amiga 4000 is one of the most powerful Amigas ever made.

As a replacement for the A3000 & A3000T, the A4000 was a combination of the A2000 (big box), A3000 (vertical slots (integrated hard drive controller) and A1200 (AGA chips). As standard it allows memory expansion for up to 18Mb RAM on the motherboard. It shipped with either a 25 MHz 68030/68882 or 25 MHz 68040 CPU. The A4000 was never intended for release, but was a prototype for a system known as the A3000 Plus which was a considerably better machine. The machine was eventually cancelled and the A4000 drafted for release due to the low cost of development.
Like the Amiga 3000, the 4000 has 2 MB of chip RAM (reserved for its coprocessors) and 4 MB of fast RAM (used directly by the 68040).
The Amiga 4000 mainboard was planned to use the AAA chip (the video custom chip designed to replace the AGA chip), the AAA chip was theoretically designed to use 8 MB FastRAM (see the "Chip RAM : ON=2MB, OFF=8MB" jumper on the motherboard), unfortunately, Commodore didn't use this chip, so this jumper is absolutely useless.
There's an internal 120 MB IDE hard disk and 4 expansion slots: three ISA slots (for PC compatible cards) and one dedicated 32 bit video slot used for graphics cards.
The Amiga 4000 works under WorKBench 3.0, a very powerful and flexible multitasking system which looks like UNIX, it can read & write directly to DOS 1.44 Mb floppy disks.
The Amiga 4000 was mainly used for video production but was in direct competition with the PC compatibles when most of its major products (ImageIn, Real 3D, & Lightwave, to name a few) were adapted for Windows.
There were in fact two models of Amiga 4000 :
- the A4000-040 released in September 92 with a Motorola 68040 Processor, 6 Mb RAM, internal 3.5" 1.76 Mb Floppy Drive and 120 Mb IDE Hard Drive,
- and the A4000-030 released March 93, with Motorola 25MHz 68030EC processor, 4Mb RAM (2Mb Chip, 2Mb Fast), 3.5" FDD, 120Mb hard disk, etc.
There was even a more powerful successor called Amiga 4000T ("T" stands for Tower). The A4000T is basically an A4000 in a full tower case with IDE & SCSI-2 Fast controllers integrated as well as 2 video slots and shipped with a 25MHz 68040 processor.
A lot of expansion hardware has been developed for the 4000/1200 : Video cards (2000 x 1500 in 24 bit), 3D cards, Wide SCSI controllers and PowerPC 604e/233 MHz accelerator cards.
The Amiga scene is still very active and great software is still being developed.
Source : Amiga Interactive Guide.
Todd Deery reports:
There was at least one other version of the Amiga 4000 available (at least in Canada) -- the Amiga 4000LC. This version contained the 25Mhz LC version of the 68040, which lacked a math coprocessor.
from Chris Coulson:

Here in the UK, the 4000-030 (not sure if this is true for the -040 as well) was also available with an 80MB HD in place of the 120MB drive.

Commodore Amiga 500

Commodore's Amiga 500 was the low-end version of the Amiga 2000 and the main competitor of Atari's 520/1040 ST range. The A500 was superior in almost every area, apart from its MIDI capabilities and the disk drive, which was not only slow but very noisy as well and a bitter feud quickly developed between owners of these rival machines.
Hardware wise, the A500 is very similar to the Amiga 1000, the main internal differences being an increase in memory fom 256 KB to 512 KB and the addition of another custom chip named "Gary" (the only Amiga chip with a male name). This is a new I/O chip that controls the disk drive and also performs address decoding. This chip is also used in the high-end A2000.
The A500 was easier to upgrade than both the ST and big box Amigas, thanks to an expansion port located in the bottom of the case. Owners could simply insert a small board which contained an extra 512 KB of Ram and a battery-backed clock. The popularity of this upgrade meant that more 1 MB software (both 1 MB versions of 512 KB software and 1 MB only software) was released for the Amiga than the ST, which had to be taken apart to expand the memory.
Over the course of the A500s lifespan several different packages were available, the most basic of which included only the computer, TV modulator and Workbench disks. A number of bundles were also sold, such as the best selling "Batman Pack" which was released in 1989 and included 3 games and Deluxe Paint 2.
The A500 was discontinued in 1991 and replaced by the short lived Amiga 500 Plus.
Pandy comments:
The Amiga 500 is a "cleaned" A1000, "cleaned" means plenty of TTL glue logic was replaced by custom IC which was named Gary. A500+ it is a new generation of custom IC's so called ECS (A500 have OCS). A500+, A3000, A600 have new graphics modes (1280 dots in line without overscan and 31Khz scanning similar to VGA - limited to 640 pixels in line with 4 colors).

Commodore Amiga 600

After being on sale for only a few months the Amiga 500 Plus was replaced with the Amiga 600 in March 1992.
The smallest Amiga ever made, it is similar in size to a laptop and weighs just 6 lbs. Originally the A600 was to be sold alongside the A500+ as a budget model to be named the Amiga 300, but instead replaced the A500+ which required a name change.
Very early models of the A600 have A300 printed on their motherboards, an indication of the confusion that was taking hold at Commodore after the surprise launch of the A500+. These early models also have a slightly different version of AmigaOS (although it is still version 2.05, it has the internal revision number 37.299) which doesn't have built-in support for the IDE or PCMCIA interfaces, the drivers for which must be loaded from a floppy disk. Later revisions of the AmigaOS (versions 37.300 & 37.350) have these drivers built-in.
The small size of the A600 also added to the incompatibility problems of the A500+. The numeric keypad had been removed from the A600 and this added hardware incompatibility to the already existing AmigaOS incompatibilities. Problems occurred with software that used the numeric keypad for inputs, mostly flight sims but also things like spreadsheets or office software, although a numeric keypad emulator was later released to address this problem.
As usual with the Amiga there were a number of official and unofficial bundles were available, with prices starting at ?399. Also released was the Amiga 600HD which included a built-in hard drive.
But with the release of the powerful new Amiga 1200 later the same year, and at the same price as the A600, a great opportunity was missed. By this time sales of the Amiga's great rival the Atari ST were slowing considerably and instead of marketing the A600 as a budget machine (as it should have been originally), it was effectively pushed out of the market thanks to competition from Commodore themselves.

Commodore Amiga CDTV

The Commodore CDTV (for Commodore Dynamic Total Vision) was a computer made by Commodore International and launched in March 1991. It was one of the first computers to come with a CD-ROM drive as standard. The CDTV was designed and marketed as a set-top box to go along with one's VCR and be used as a CD-player and games console. It was created as a direct competitor to the CD-i, with neither having any real commercial success. Though the CDTV was based entirely on Amiga hardware it was marketed as Commodore CDTV with the Amiga name omitted from product branding.

The CDTV was essentially an Amiga 500, replacing the floppy drive with a single-speed CD-ROM drive. But unlike its progenitor, CDTV was intended as a media appliance rather than a personal computer. As such, its housing had dimensions and styling compatible with most stereo components, and came with an infrared remote control. Similarly, it was initially sold without keyboard and mouse (which could be added separately). Commodore chose Amiga enthusiast magazines as its chief advertising channel, but the Amiga community on the whole avoided the CDTV in the expectation of an add-on CD-ROM drive for the Amiga, which eventually came in the form of the A570.

The CDTV was supplied with the already obsolete AmigaOS 1.3, rather than the more advanced 2.0 release. The CDXL motion video format was primarily developed for the CDTV making it one of the earliest consumer systems to allow video playback from CD-ROM.

The CDTV debuted in America in March 1991 (CES, Las Vegas) and in the UK (Word of Commodore 1991 at Earls Court, London). It was advertised at Pound 499 for the CDTV unit, remote control and two titles. Though Commodore later developed an improved and cost-reduced CDTV-II it was never released and the CDTV was eventually replaced with the Amiga CD32 following its release in 1993.


Technical Specifications

CPU: Motorola 68000 at 7.16 MHz (NTSC) or 7.09 MHz (PAL)
Memory:
1 MB Amiga Chip RAM
2 kB non-volatile RAM
256 kB Kickstart ROM
256 kB CDTV firmware ROM
Chipset: Original Chip Set (OCS)
Single-speed CD-ROM drive (proprietary controller)
OS: AmigaOS 1.3 and CDTV firmware
Wireless infrared remote control/gamepad
Connectors/Ports:
NTSC model:
RF audio/video out (RCA)
Composite video out (RCA)
S-Video out (4-pin mini-DIN)
PAL model:
RF audio/video out (RF loop through)
Composite video out (RCA)
Analogue RGB video out (DB-23M)
Audio out (2xRCA and 6.35 mm stereo jack)
Mouse (4 pin mini-DIN)
Keyboard (5 pin mini-DIN)
RS-232 serial port (DB-25M)
Centronics style parallel port (DB-25F)
Floppy disk drive port (DB-23F)
MIDI (In and Out)
Proprietary card slot for 64 or 256 kB non-volatile memory cards

Infos from: Wikipedia

Commodore PET

The PET (Personal Electronic Transactor) was a home-/personal computer produced by Commodore starting in 1977. Although it was not a top seller outside the Canadian, US, and UK educational markets, it was Commodore's first full-featured computer and would form the basis for their future success.


Origins and the early models

Design of the chiclet keyboard of the PET 2001 seriesIn the 1970s, Texas Instruments was the main supplier of CPUs for use in calculators. Many companies sold calculator designs based on their chip sets, including Commodore. However, in 1975 TI increased the price to the point where the chip set alone cost more than what TI sold their entire calculators for, and the industry they had built up was frozen out of the market.

Commodore responded by looking for a chip set of their own they could purchase outright, and quickly found MOS Technology, Inc. who were bringing their 6502 microprocessor design to market. Along with the company came Chuck Peddle's KIM-1 design, a small computer kit based on the 6502. At Commodore, Peddle convinced Jack Tramiel that calculators were a dead-end. Instead they should focus on making a 'real' machine out of the KIM-1, and selling that for much higher profits. Tramiel demanded that Peddle, and Tramiel's son, Leonard, create a computer in time for the June 1977 Consumer Electronics Show, and gave them six months to do it.

The result was the first all-in-one home computer, the PET. The first model was the PET 2001, including either 4 KB (the 2001-4) or 8 KB (2001-8) of 8-bit RAM. It was essentially a single-board computer with a new display chip (the MOS 6545) driving a small built-in monochrome monitor with 40x25 character graphics. The machine also included a built-in Datassette for data storage located on the front of the case, which left little room for the keyboard. The 2001 was announced at the '77 Winter CES in January 1977 and the first 100 units were shipped in mid October 1977. However they remained back-ordered for months, and to ease deliveries they eventually cancelled the 4 kB version early the next year.

Although the machine was fairly successful, there were frequent complaints about the tiny calculator-like keyboard, often referred to as a 'chiclet keyboard' because the keys resembled the popular gum candy. This was addressed in upgraded 'dash N' and 'dash B' versions of the 2001, which put the cassette outside the case, and included a much larger keyboard with a full stroke non-click motion. Internally a newer and simpler motherboard was used, along with an upgrade in memory to 8, 16, or 32 KB, known as the 2001-N-8, 2001-N-16 or 2001-N-32, respectively.

Sales of the newer machines was strong, and Commodore then introduced the models to Europe. However there was already a machine called PET for sale in Europe from the huge Dutch Philips company, and the name had to be changed. The result was the CBM 3000 series ('CBM' standing for Commodore Business Machines), which included the 3008, 3016 and 3032 models. Like the 2001-N-8, the 3008 was quickly dropped.

CBM Model 4032
CBM 4040 dual disk drive (5.25')


Education, business, and computer science

The final version of what could be thought of as the 'classic' PET was the PET 4000 series.

This was essentially the later model 2000 series, but with a larger black-and-green monitor and a newer version of Commodore's BASIC programming language.

By this point Commodore had noticed that many customers were buying the 'low memory' versions of the machines and installing their own RAM chips, so the 4008 and 4016 had the sockets punched out of the motherboard.

The 4032 was a huge success in schools, where its tough all-metal construction and all-in-one design made it better able to stand up to the rigors of classroom use. Just as important in this role was the PET's otherwise underutilized IEEE 488 port. Used wisely, the port could be used as a simple 'network' and allowed printers and disk drives (then very expensive) to be shared among all of the machines in the classroom.

Two more machines were released in the PET series. The CBM 8000 included a new display chip which drove an 80x25 character screen, but this resulted in a number of software incompatibilities with programs designed for the 40 column screen, and it appears to have been unpopular as a result.

The machine shipped with 32 kB standard as the 8032, but allowed another 64 kB to be added externally. Later the upgrade was installed from the factory, creating the 8096.

The last in the series was the SP9000, known as the SuperPET or MicroMainframe. This machine was designed at the University of Waterloo for teaching programming. In addition to the basic CBM 8000 hardware, the 9000 added a second CPU in the form of the Motorola 6809 and included a number of programming languages including BASIC in ROM for the 6502 and APL, COBOL, FORTRAN, Pascal and a 6809 assembler on floppies for the 6809. It also included a terminal program which allowed the machine to be used as a 'smart terminal' as well, so this single machine could replace many of the boxes currently in use at the university. Additionally this machine became a remote development environment where the user could later upload their creation to a mainframe after completing development and testing on the SuperPET.

Commodore tried to update the PET line with a new redesign called the CBM-II series (also known as the B series). These were not as successful and were ultimately abandoned. However, due to demand, the original PET machines were revived and the CBM-II case style was retained. These were known as the SK's (due to the separated keyboard). They also had a swivel monitor. Originally, standard 8032 boards were retrofitted into these cases. Later the SK models got a new mainboard that already included the 64 kB extension directly on the board and were sold as 8296 or, with a built-in 8250 dual disk drive, as 8296-D.

Although not officially a member of the PET series, in 1983 Commodore packaged C64 motherboards in PET 4000-series cases to create the Educator 64. This was an attempt to retake some of the education market they had largely lost by then to the Apple II.


The graphics issue

In the home computer market the line was soon outsold by machines that included bitmapped color graphics and sound, mainly the Apple II (introduced later in 1977, the same year as the PET 2001), Atari 400/800 (1979), and, in particular, Commodore's own bestselling VIC-20 (1980/81). The mainstream business computer market of the time considered colors and graphics somewhat less of an issue, a view that would change toward the end of the 1980s.

Bitmapping and colors aside, the main limitation of the PET's graphics capabilities was that the character set was 'hardwired' in ROM. On many of the PET range's home computer rivals, the look-up address of the character graphics could be changed and pointed to RAM, where new characters could be drawn by a programmer to create custom graphics shapes. From a programming point of view, this was a relatively simple method of producing good-looking graphics images, and because of this, as well as the acceptable speed obtainable by a BASIC program moving character objects on the screen compared to bitmap graphics, many programs with a certain amount of graphics, including a fair amount of games, were made this way even on bitmap-capable machines. The PET's lack of the character set remapping feature must therefore be said to constitute a major weakness in the machine's design.

Somewhat offsetting this drawback, the PET's ROM-restricted character set—an ASCII-1963 deviation known as PETSCII—was one of the most varied and flexible of the era, allowing PET games with rudimentary graphics to be created, exemplified by clones of video games such as Space Invaders. Also, the many popular text adventure games of the time, some multiplatform, some created for the PET line, did not need graphics at all. For specialized applications, alternative character sets could be programmed into an EPROM inserted in the character set ROM socket. Alternative character set EPROMs with diacritics and mathematical symbols were available in the aftermarket.


Model summary

PET 2001 series / 2001-N & -B series, CBM 3000 series

CPU: 6502, 1 MHz
RAM: 4 or 8 KB / 8, 16, or 32 KB
ROM: 18 KB, including BASIC 1.0 / 20 kB, including BASIC 2.0
Video: discrete TTL video circuit, 9' monochrome monitor, 40x25 character display
Sound: none / single piezo 'beeper' (optional external speaker driven by MOS 6522 CB2 pin)
Ports: 2 MOS 6520 PIA, MOS 6522 VIA, 2 Datassette (1 used / 1 on the back), 1 IEEE-488
Notes: 69 key chiclet keyboard and built-in Datassette / full-sized, full-travel keyboard, no built-in Datassette

PET 4000 series / CBM 8000 series

CPU: MOS 6502, 1 MHz
RAM: 8, 16, or 32 kB / 32 or 96 kB
ROM: 20K, including BASIC 4.0
Video: MOS 6545, 9' or 12' / 12' monochrome monitor, 40x25 / 80x25 character display
Sound: single piezo 'beeper' (optional external speaker driven by MOS 6522 CB2 pin)
Ports: 2 MOS 6520 PIA, MOS 6522 VIA, 2 Datassette ports (1 on the back), 1 IEEE-488
Notes: basically an upgraded 2001 / basically a 4000 with 80 columns and slightly different keyboard with smaller (11 key) numeric pad

SuperPET 9000 series

CPU: MOS 6502 and Motorola 6809, 1 MHz
RAM: 96 KB
ROM: 48 KB, including BASIC 4.0 and other programming languages
Video: MOS 6545, 12' monochrome monitor, 80x25 character display
Sound: single piezo 'beeper' (optional external speaker driven by MOS 6522 CB2 pin)
Ports: MOS 6520 PIA, MOS 6522 VIA, MOS 6551 ACIA, 1 RS-232, 2 Datassette ports (1 on the back), 1 IEEE-488
Notes: basically an 8000 with ROMs for programming languages, it also had three character sets, and an RS-232 for use as a terminal

Peripherals

Commodore Business Machines made a variety of disk drives available for the PET, using the IEEE 488 interface, including:

Commodore 2031 single disk drive
Commodore 4040 dual disk drive
Commodore 8050 dual disk drive
Commodore 8250 'quad density' dual disk drive
Commodore 8280 dual disk drive (8')
Commodore SFD-1001 'quad density' single disk drive
Commodore 9060 hard drive (5 Megabytes)
Commodore 9090 hard drive (7.5 Megabytes)

Easter Egg

In PET Microsoft Basic, type the command 'WAIT 6502.' The screen will fill with the text 'MICROSOFT.'

Infos from: Wikipedia

Commodore Plus-4 - C16 - C116

The Commodore 16 was a home computer made by Commodore with a 6502-compatible 7501 CPU, released in 1984. It was intended to be an entry-level computer to replace the VIC-20 and it often sold for USDollar99. A cost-reduced version, the Commodore 116, was sold only in Europe.


Intention
The C16 was intended to compete with other sub-Dollar100 computers from Timex Corporation, Mattel, and Texas Instruments (TI). Timex's and Mattel's computers were less expensive than the VIC, and although the VIC offered better expandability, a full-travel keyboard, and in some cases more memory, the C16 offered a chance to improve upon those advantages. The TI-99/4A was priced in-between Commodore's VIC-20 and C64, and was somewhat between them in capability, but TI was lowering its prices. On paper, the C16 was a closer match for the TI-99/4A than the aging VIC-20.

Additionally, Commodore president Jack Tramiel feared that one or more Japanese companies would introduce a consumer-oriented computer and undercut everyone's prices. Although the Japanese would soon dominate the U.S. video game console market, the feared dominance of the home computer field never materialized. Additionally, Timex, Mattel, and TI departed the market before the C16 was released.


Description
Outwardly the C16 resembled the VIC-20 and the C64, but with a black case and white/light gray keys. Performance-wise located between the VIC and 64, it had 16 kilobytes of RAM with 12 KB available to its built-in BASIC interpreter, and a new sound and video chipset offering a palette of 128 colors (in reality 121, since the system had a 16 base colors and 8 shades but black always remained black, with all 8 shades), the TED (better than the VIC used in the VIC-20, but lacking the sprite capability of the VIC-II and advanced sound capabilities of the SID, both used in the C64). The ROM resident BASIC 3.5, however, was more powerful than the VIC-20's and C64's BASIC 2.0, in that it had commands for sound and bitmapped graphics (320x200 pixels), as well as simple program tracing/debugging.

From a practical user's point of view, three tangible features the C16 lacked were a modem port and VIC/C64-compatible Datassette and game ports. Commodore sold a C16 family-specific cassette player (the Commodore 1531) and joysticks, but third-party converters to allow the use of the abundant, and hence much less expensive, VIC/C64-type units soon appeared. The official reason for changing the joystick ports was to reduce RF interference. The C16's serial port (Commodore's proprietary 'serial IEEE-488 bus', no relation to RS-232 and the like) was the same as that of the VIC and C64, which meant that printers and disk drives, at least, were interchangeable with the older machines.

The Commodore 16 was one of three computers in its family. The even less successful Commodore 116 was functionally and technically similar but shipped in a smaller case with a rubber chiclet keyboard and was only available in Europe. The family's flagship, the Commodore Plus/4, shipped in a smaller case but had a 59-key full-travel keyboard (with a specifically advertised 'cursor key diamond' of four keys, contrasted with the VIC and C64's two + shift key scheme), 64 KB of RAM, a modem port, and built-in entry-level office suite software.

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The Commodore Plus/4 was a home computer released by Commodore International in 1984. The 'Plus/4' name refers to the four-application ROM resident office suite (word processor, spreadsheet, database, and graphing); it was billed as 'the productivity computer with software built-in'. It had some success in Eastern Europe, but was less popular in Western Europe . A total flop in the United States, it was derided as the 'Minus/60'—a pun on the difference between the Plus/4 and the dominant Commodore 64.

Background
In the early 1980s, Commodore found itself engaged in a price war in the home computer market. The VIC-20 resulted from MOS Technology designing a video chip it couldn't sell, and companies like Texas Instruments and Timex Corporation undercutting the price of Commodore's PET line. The Commodore 64, the first 64-KB computer to sell for under USDollar600, was another salvo in the price war but it was far more expensive to make than the VIC-20 because it used discrete chips for video, sound, and I/O. Commodore president Jack Tramiel wanted a new computer line that would use fewer chips and at the same time address some of the user complaints about the VIC and C64.

Commodore's third salvo — which, as it turned out, was fired just as most of Commodore's competition was leaving the home computer market — was the C116, C16, and Plus/4. There were also prototypes of a 232, basically a 32k version of the Plus /4 without the software ROMs, and a V364 which had a numeric keypad and built in voice synthesis. The latter two models never made it to production. All these computers used a MOS 7501 CPU (6502 compatible but Approx.75 percent faster) and a MOS Technology TED all-in-one video, sound, and I/O chip. The Plus/4's design is thus philosophically closer to that of the VIC-20 than of the C64.

The Plus/4 was the flagship computer of the line. The Plus/4 had 64 KB of memory while the C16 and 116 had 16 KB. The Plus/4 had built-in software, whereas the others did not. The Plus/4 and C16 had full-travel keyboards; the 116 used a rubber chiclet keyboard like less-expensive Timex-Sinclair computers and the original IBM PCjr. The C116 was only sold in Europe. All of the machines were distinguished by their dark gray cases and light gray keys.

The Plus/4 was introduced in June 1984 and priced at USDollar299. It was discontinued in 1985. It is not completely clear whether Commodore's intent was to eventually totally replace the C64 with the Plus/4, or whether they wanted to attempt to expand the home computer market and sell the Plus/4 to users who were more interested in serious applications than gaming. However, the Plus/4 succeeded at neither and quickly disappeared.


Plus/4 strengths

Commodore Plus/4 with accessories. Clockwise from top left: power supply, joystick, 1531 tape recorder with tapes.The TED offered 121-color (15 colors x 8 luminance levels + black) video, a palette matched only by Atari Computers at the time, and 320x200 video resolution, which was standard for computers intended to be capable of connecting to a television. The Plus/4's memory layout gave it a larger amount of user-accessible memory than the C64, and its BASIC programming language was vastly improved, adding sound and graphics commands as well as looping commands that improved program structure. Commodore released a high-speed floppy disk drive for the Plus/4, the Commodore 1551, which offered much better performance than the C64/1541 combination because it used a parallel interface rather than a serial bus. (The Plus/4 did not have the parallel interface built-in; it was provided by a plug-in cartridge supplied with the drive).

Unlike the C64, the Plus/4 had a built-in MOS Technology 6551 UART chip (the C64 emulated the 6551 in software). This allowed the Plus/4 to use high-speed modems without additional hardware or software tricks (the C64 required specially written software to operate at 2400 bit/s). However, since most people only could afford 300- or 1200-bit/s modems in 1984, and Commodore never released a 2400-bit/s modem, this feature went largely unnoticed. The Plus/4 keyboard had a separately placed 'diamond' of four cursor keys, presumably more intuitive in use than the VIC's and C64's two shifted cursor keys. Also, for serious programmers, the Plus/4 featured a ROM-resident machine code monitor, which rekindled a tradition from the first Commodore computers, the PET/CBM series.

While the C64 had the advertised 64 KB of RAM installed, only about 38 KB was available for BASIC programs. The Plus/4's BASIC V3.5 made 59 KB available, aided by its memory map that placed I/O at the top of memory (DollarFD00). In addition, the Plus/4's CPU was about 75 percent faster than the C64's.


Plus/4 weaknesses
The Plus/4 had three shortcomings, which proved fatal: unlike the C64's VIC II, the TED had no sprite capability, which strongly limited its video game graphics capabilities. Also, its tone generator was much closer to the VIC in quality than to the C64's SID, which, again, made the Plus/4 less attractive to game developers. Finally, the lack of these capabilities made C64 software compatibility impossible. Commodore may not have believed this to be a problem, as the successful C64 was incompatible with most VIC-20 software — but the C64 had developed a large software library by 1984, and while the C64 was a significant upgrade to the VIC-20 in almost every way, the Plus/4 was not.

Another problem that kept the Plus/4 from selling was that even though the three machines (116,C16 and Plus/4) were all compatible with one another, developers tended to write programs for the lowest common denominator in a computer family. So as not to alienate buyers of the 116 and C16, which were intended to be the largest selling machines in this series, most software was designed to run in 16k and the extra memory on the Plus/4 was not as widely supported as it could have been. Also, most development for these machines was in Europe. Few North American developers leapt at the chance to write programs for these machines.

Peripheral compatibility with the C64 was inconsistent. The Plus/4's serial, user, and video ports were compatible with the C64, but the Datasette port was changed, rendering previous units incompatible without third-party adapters that only became available later. This also posed a problem for the many third-party C64 printer interfaces that allowed one to connect a standard Centronics parallel printer to the Commodore serial port. Since most of these interfaces connected to the Datasette port to get +5 volts for power, they were incompatible with the Plus/4 unless the user modified the interface and risked voiding the warranty. For a computer intended to be used for productivity applications, this was a heavy weakness. Additionally, with the Plus/4, Commodore abandoned the Atari-style joystick ports used on the C64, replacing them with a proprietary mini-DIN port that was said to be less prone to emit RF interference. While this may have been seen as an advantage by the Federal Communications Commission and other regulatory agencies, end users did not share this view.

This made upgrading to the Plus/4 from the VIC-20 or C64 more expensive, since the user in many cases would have to buy new peripherals in addition to the new computer. It also made the Plus/4 less attractive to new buyers, since VIC and C64 peripherals were more plentiful and less expensive than their Plus/4 counterparts. The street price for a complete C64 system was lower than that of a comparable system based on the Plus/4.

The Plus/4, unlike the C64 and most other computers of its time (with the notable exception of the Coleco Adam), was equipped with ROM-resident application software (developed for Commodore by TriMicro). Unfortunately, the application suite, featuring a word processor, spreadsheet, database, and graphing, was completely inadequate for the Plus/4's originally intended market of business and professional users. Better business software packages were available for other systems, including the C64.

Most of the developers of the Plus/4 also worked on the later Commodore 128 project, which was much more successful. The lead hardware designer Bil Herd commented directly on the wikipedia article adding: The TED series (Plus4) was specifically designed to not encroach on the successful C64, it was designed to sell for Dollar49 and to go head to head with the Timex/Sinclair computer line, specifically the color Timex (Spectrum?) Targeting the office more than the game market, the smallest version of the computer had a total of 9 IC's, cheapness was the main metric as defined by Jack Tramiel. After Tramiel left Commodore, the remaining management seemed to not know what to do with the Plus4 line which resulted in untold variations and lack of focus on the targeted market. Since most of the management at that time had only experienced the C64, they tried to market it as another C64 which was exactly what Tramiel had set out not to do.

This shortcomings of the end product were the inspiration for the C128 series as the designers calculated that if they created a computer that was compatible with the C64 that ultimately management and marketing could not damage the C64 software base (much) in spite of how they were to take the product to market.


Specifications
CPU: MOS_Technology 7501, 1.77 MHz (PAL) / 1.79 MHz (NTSC)
RAM: 64 KB, of which nearly 60 KB available to BASIC users
ROM: 64 KB including Commodore BASIC 3.5, machine code monitor; TRI-Micro's '3 Plus 1' (word processor, spreadsheet, database, graphing)
Text mode: 40x25 characters (PETSCII)
Graphics modes: 160x200 (lores) / 320x200 (hires), 121 colors
I/O ports:
Tape connector (for Commodore 1531 Datassette; incompatible with C64)
Cartridge slot (incompatible with C64)
Two game controller ports (incompatible with C64)
Commodore serial bus
User port (for modems and nonstandard devices)
Composite video connector incl. mono audio signal
RF modulator to TV antenna connector

Infos from: Wikipedia

Commodore VIC-20

Processor MOS Technology 6502 @ 1MHz
Memory 5KB - 64KB
OS Commodore BASIC 2.0


The VIC-20 (Germany: VC-20; Japan: VIC-1001) is an 8-bit home computer. It was made by Commodore Business Machines, with 5 KB RAM and a MOS 6502 CPU. The machine's external design was later used by the Commodore 64 and C16. The VIC-20 was released in Japan in 1980, and in the U.S. and Europe in 1981, roughly three years after Commodore's first personal computer, the PET. The VIC-20 was the first microcomputer to sell one million units.


History

Origin, marketing

The VIC-20 was intended to be more economical than the PET computer. The VIC-20's video chip, the MOS Technology VIC was a general-purpose color video chip designed by Al Charpentier in 1977 and intended for use in inexpensive display terminals and game consoles, but Commodore couldn't find a market for the chip. With Apple II gaining momentum with the advent of VisiCalc in 1979, Jack Tramiel wanted a product out that would compete in the same segment, to be presented at the January 1980 CES. For this reason Chuck Peddle and Bill Seiler started to design a computer named TOI (The Other Intellect).

The TOI computer failed to materialize, much due to the fact that it required an 80-column character display which in turn required the MOS Technology 6564 chip, which could not be used since it required very expensive static RAM to operate fast enough. In the meantime, freshman engineer Robert Yannes at MOS Technology (then a part of Commodore) had designed a computer in his home dubbed the MicroPET and finished a prototype with some help from Al Charpentier and Charles Winterble. When Jack Tramiel was confronted with this prototype he immediately said he wanted it to be finished and ordered it to be mass produced following a limited demonstration on the CES, since the TOI had not yet been finished.

The very hackish prototype produced by Yannes had very few of the features required for a real computer, so Robert Russell at Commodore headquarters had to coordinate and finish large parts of the design under the codename Vixen. The parts contributed by Russell included a port of the operating system (kernel and BASIC interpreter) taken from John Feagans design for the Commodore PET, a character set with the characteristic PETSCII, an Atari 2600-compatible joystick interface and the cartridge port. The serial IEEE 488-derivative interface was designed by Glen Stark. Some features, like the memory add-in board, were designed by Bill Seiler. At the time, Commodore had an oversupply of 1Kbitx4 SRAM chips, so Tramiel demanded that these be used in the new computer. The end result is arguably closer to the PET or TOI computers than to Yannes prototype, albeit with a 22-column VIC chip instead of the custom chips designed for the more ambitious computers.

In April 1980 at a meeting of general managers outside of London, Jack Tramiel declared that he wanted a lowcost color computer. When most of the GMs argued against it, he said, 'the Japanese are coming, so we will become the Japanese.' This was in keeping with Tramiel's philosophy which was to make 'computers for the masses, not the classes.' The concept was championed at the meeting by Michael Tomczyk, newly hired marketing strategist and assistant to the president; Tony Tokai, General Manager of Commodore-Japan, and Kit Spencer, the U.K.'s top marketing executive.

When they returned to California from that meeting, Tomczyk wrote a 30 page memo detailing recommendations for the new computer and presented it to Tramiel. Recommendations included programmable function keys, full size typewriter style keys, built-in RS-232. Tomczyk insisted on 'user friendliness' as the prime directive for the new computer and proposed a retail price of Dollar299.95. He recruited a marketing team and a small group of computer enthusiasts, and worked closely with colleagues in the U.K. and Japan to create colorful packaging, user manuals, and the first wave of software programs (mostly games and home applications). Scott Adams was contracted to provide a series of cartridge-based adventure games. Tomczyk's account of the story is told in his 1984 book, The Home Computer Wars.

While the PET was sold through authorized dealers, the VIC-20 primarily sold at retail, especially discount and toy stores, where it could compete more directly with game consoles. It was the first computer to be sold in K-Mart. Commodore took out advertisements featuring actor William Shatner of Star Trek fame as its spokesman, asking, 'Why buy just a video game?'. Television personality Henry Morgan (best known as a panelist on the TV show What's My Line?) became the ironic voice on a series of clever Commodore product ads.

The VIC-20 had 5K of Ram, which netted down to 3.5K on startup, which is the equivalent to the words and spaces on one sheet of typing paper. The computer was expandable to 32k with an add-on memory cartridge. Although the VIC-20 was criticized in print as being underpowered, the strategy worked: in 1982 it was the best-selling computer of the year, with 800,000 machines sold, and in January 1983 it passed the 1 million unit mark—a first in computer history. At its peak, 9,000 units per day were produced, and a total of 2.5 million units were sold before it was discontinued in January 1985, when Commodore repositioned the C64 as its entry-level computer due to the forthcoming release of the C128 and Amiga (the latter taking Commodore into the 16-bit world).
In 1981, Tomczyk contracted with an outside engineering group to develop a direct-connect modem-on-a-cartridge (the VICModem) which at Dollar99 became the first modem priced under Dollar100. The VICModem was also the first modem to sell over 1 million units. VICModem was packaged with Dollar197.50 worth of free telecomputing services from the Source, CompuServe and Dow Jones. Tomczyk also created an entity called the Commodore Information Network to enable users to exchange information and take some of the pressure from Customer Support inquires, which were straining Commodore's lean organization. In 1982, this network accounted for the largest traffic on CompuServe, which, it can be argued, was an early implementation of Internet-style user groups.


Applications

Because of its small memory and low-resolution display compared to some other computers of the time, the VIC-20 was primarily used for educational software and games. However, productivity applications such as home finance programs, spreadsheets, and communication terminal programs were also made for the machine. Its high accessibility to the general public meant that quite a few software developers-to-be cut their teeth on the VIC-20, being introduced to BASIC programming, and in some cases going further to learn assembly or machine language. Several computer magazines sold on newsstands, such as Compute! and CBM-produced publications, offered programming tips and type-in programs for the VIC-20. Many VIC users learned to program by entering, studying, running, and modifying these type-ins.

The ease of programming the VIC and availability of an inexpensive modem combined to give the VIC a sizable library of public domain and freeware software, although much smaller than that of the C64. This software was distributed on online services such as CompuServe, BBSs, and via user groups.

As for commercial software offerings, an estimated 300 titles were available on cartridge, and another 500+ titles were available on tape. By comparison, the Atari 2600, the most popular of the video game consoles at the time, had a library of about 900 titles near the end of its production life (many were variations of another title). Cartridge games were ready to play as soon as VIC-20 was turned on, as opposed to games on tape which required loading. Titles on cartridge included Gorf, Cosmic Cruncher, Sargon II Chess, and many others.

One of the most popular cassette games was Blitz, written by Simon Taylor and published by Commodore, selling many tens of thousands of copies, and remaining in the top ten computer games listings for six months. The game involved flying over a city of skyscrapers, and flattening the buildings one by one by bombing them until the city was flat. The aircraft descended a line at a time, and if your bombing had not been accurate enough, you would hit the skyscraper and crash.


Description

Basic features

The VIC-20 had proprietary connectors for program/expansion cartridges and a tape drive (PET-standard Datassette). It came with 5 KB RAM, but 1.5 KB were used by the system for various things, like the video display (which had a rather unusual 22x23 char/line screen layout), and other dynamic aspects of the ROM-resident BASIC interpreter and KERNAL (a low-level operating system). Thus, 3.5 KB of BASIC program memory for code and variables was available to the user of an unexpanded machine.

The computer also had a serial bus (a serial version of the PET's IEEE-488 bus) for daisy chaining disk drives and printers; a TTL-level 'user port' with RS-232 and Centronics signals (most frequently used as RS-232, for connecting a modem); and a single DE-9 game controller port, compatible with the digital joysticks and paddle (game controller)s used with Atari 2600 videogame consoles and, later, the C64 (the use of a standard port ensured ample supply of Atari-manufactured and other third-party joysticks; Commodore itself offered an Atari joystick under the Commodore brand).

Importantly, like most video game consoles at the time the VIC had a cartridge port to allow for plug-in cartridges with games and other software as well as for adding memory to the machine. Port expander boxes were available from Commodore and other vendors to allow more than one cartridge to be connected at a time.

The graphics capabilities of the VIC chip (6560/6561) were limited but flexible. At startup the screen showed 176 pixels in width and 184 in height, with a fixed-colour border to the edges of the screen; since a NTSC or PAL screen has a 4:3 width-to-height ratio, each VIC pixel was much wider than it was high. The screen normally showed 22 columns and 23 rows of 8-by-8-pixel characters; it was possible to increase these dimensions but the characters would soon run out the sides of the monitor. Like on the PET, 256 different characters could be displayed at a time, normally taken from one of the two character generators in ROM (one for upper-case letters and simple graphics, the other for mixed-case -- non-English characters were not provided). In the usual display mode, each character position could have its foreground colour chosen individually, and the background and screen border colours were set globally. A character could be made to appear in another mode where each pixel was chosen from 4 different colours: the character's foreground colour, the screen background, the screen border and an 'auxiliary' colour; but this mode was rarely used since it made the pixels twice as wide as they normally were.

The VIC chip did not provide for a direct full-screen, high-resolution graphics mode. It did, however, allow the pixel-by-pixel depictions of the on-screen characters to be redefined (by using a character generator in RAM), and it allowed for double-height characters (8 pixels wide, 16 pixels high). It was possible to get a fully-addressable screen, slightly smaller (160 by 160) than normal, by filling the screen with a sequence of 200 different double-height characters, then turning on the pixels selectively inside the RAM-based character definitions. (The 200-character limitation was so that enough bytes would be left over for the screen character grid itself to remain addressable by the VIC chip.) The Super Expander cartridge provided such a mode in BASIC, although it often had to move the BASIC program around in memory to do it. It was also possible to fill a larger area of the screen with addressable graphics using a more dynamic allocation scheme, if the contents were sparse or repetitive enough. This was used, for instance, by the game Omega Race. The VIC chip did not support sprites.

The VIC chip had readable scan-line counters but could not generate interrupts based on the scan position (as the VIC-II chip could). Thus it was possible, but difficult, to switch graphics modes dynamically during a single screen scan. The VIC chip could also process a light pen signal (an light pen input was provided on the DE-9 joystick connector) but few of those ever appeared on the market.

The VIC chip had three rectangular-wave sound generators (about an octave apart) plus a white noise generator. There was only one volume control.

Memory expansion

The VIC-20's RAM was expandable with plug-in cartridges using the same expansion port as programs. RAM cartridges were available in several sizes: 3K (with or without an included BASIC extension ROM), 8K, 16K, 32K and 64K, the latter two only from third-party vendors. The internal memory map was reorganised with the addition of each size cartridge, leading to the situation that some programs would only work if the right amount of memory was present (to cater for this, the 32K cartridges had switches, and the 64K cartridges had software setups, allowing the RAM to be enabled in user-selected sections).

The most visible part of memory that was reorganised with differing expansion memory configurations was the video memory (with text and/or graphics display data). This was because the free memory had to remain contiguous for the BASIC interpreter to be able to use it. An unexpanded VIC had 1K of system memory, followed by a 3K 'hole', then 4K of contiguous user memory up to address 8191. The 3K cartridge would fill the 'hole', so on unexpanded and +3K VICs the video area was placed at the top of user memory (8K - 512). If an 8K or 16K cartridge was added instead, this memory appeared at addresses above 8K; the video memory was then placed at the start of user memory at 4K, just above the 'hole', to provide the maximum amount of contiguous user memory.

Some 64K expansion cartridges allowed the user to copy ROM images to RAM. The more advanced versions even contained an 80-character video chip and a patched BASIC interpreter which gave access to 48K of the memory and to the 80-column video mode. As the latter type of cartridges, marketed primarily in Germany, weren't released until late 1984—two years after the appearance of the more capable C64—they went by mostly unnoticed.


The VIC's name(s)

* The name 'VIC' came from the Video Interface Chip, which, despite its designation, also handled all the sound synthesis in the VIC-20. The VIC chip's successor, the graphics-and-RAM-refresh VIC-II, was used to great success in Commodore's later best-selling machine, the C64, and also in the dual video output C128 for that computer's 40-column/composite video graphics.
* The VIC-20 was originally meant to be called Vixen, but this name was inappropriate in Germany, Commodore's second most important market, because it sounds like wichsen, a German language slang word for 'masturbate'. VIC, which was subsequently chosen, has a similar problem—it can be pronounced like fick[en], the German word for 'fuck'. Therefore the VIC-20 was finally marketed as the VC-20 'Volkscomputer' in German-language countries.
* In Japan the VIC-20 was marketed as the VC-1001 (1980).
* The 20 in VIC-20 has nothing to do with technical specs, Michael Tomczyk thought that VIC sounded like a truck drivers name so he insisted on adding 20 as a friendly number for a friendly computer. According to reports, the original name was going to be VIC-22 (based on the screen width) but 20 was chosen as a friendlier name. (citation needed).


VIC trivia

* BASIC programs running on a fully expanded VIC-20 could use at most 24K RAM. Any extra occupied the memory space used by ROM cartridges, i.e. commercial software like games and other applications. This allowed people to copy cartridges to tape and distribute them to their friends, who could then load the tape into the top 8K of their 32K RAM packs.
* An anecdotal bit of evidence to support Commodore's statement that the VIC-20 could be used not only for games but also as a serious introduction to computing, can be said to originate in the fact that a young Linus Torvalds was given a VIC-20 as his first computer. Torvalds later upgraded to a Sinclair QL, then to a 386 PC. Torvalds later went on to write the Linux operating system kernel.


Notes

Both the VIC 20 and C64 could be hooked into external electronic circuitry, using parts available from parts outlets like Radio Shack and Maplin. Interfaces were designed to use either the joystick ports, printer port, or the expansion ports, which exposed various analog to digital, memory bus, and other internal I/O circuits to the experimenter. The BASIC language could then be used (using the PEEK and POKE commands) to perform data acquisition from temperature sensors, control robotic stepper motors, etc. The VIC 20 did not originally have a disk drive available for sale, with only a relatively high cost tape recorder system (using audio cassette tapes). Many experimenters built adaptors that allowed any conventional audio cassette recorder to be used for program and data storage.



Infos from Wikipedia