8Bit computers

Retro computer history from Atari 2600 to NES (1980-1985)



This is the story of the 8bit microcomputers, from 1980 to 1985, from the first mass-market console (Atari 2600) to the Video Game Crash of 1983, up to the NES success in the following years.

In this story Atari, Commodore, and Nintendo are the game changer, together with other players like Mattel and Texas Instruments. Atari created the market, Commodore pushed the 8-bit computer era, Nintendo rescued it.

In the hype (mid '80) I was eleven years old in a little country called Italy when the 8-bit computer era was growing.

I was able to get a Vic20 and after that, the C/64, thank you to the Jack Tramiel's idea to sold computers into the retail stores instead of only electronics or computer hobbyist specialty stores. Commodore computers will change my life forever.

So I decided to run through again that years adding my experience: this is the book you are reading, for less than a Starbucks' Frappuccino.

Editor note:

This book is still in draft form and will be released at no charge for a limited period of time. Please feel free to add comment on the following page

Alive and kicking

It is interesting how the retro computer like NES and C/64 are still alive. On April 2019 ZeroPaige announced a Super Mario Bros port for the C/64, then Nintendo sued in a rush.

Considering C/64 birth date back to 1982, it is impressive how long a 37 years old platform is still getting software for it, although authors are enthusiasts and somewhat described as “nerd”.

This book is dedicated to the Men and the Women who built the Commodore Vic20 and changed my life forever.

Pong and the others: Atari, where everything started

In 1971, Nolan Bushnell and Ted Dabney founded a small engineering company, Syzygy Engineering, that designed and built Computer Space, the world's first commercially available arcade video game, for Nutting Associates. On June 27, 1972, the two incorporated Atari, Inc. and soon hired Al Alcorn as their first design engineer.

Computer Space was the first “coin-op” game, and was realized without even a microprocessor!

The entire computer system is a state machine made of 74-series TTL chips. Graphic elements are held in diode arrays.1

Cabinet of Computer Space
Cabinet of Computer Space

Atari was a “startup” of the '70, and even Steve Jobs and Wozniak worked here (Bushnell could have been an Apple cofounder himself, but turned down the opportunity).2

Atari history wrap-up

Atari had many souls: we can split its history into three parts.

The first company lived from 1972 to 1984. After the video game crash of 1983, Jack Tramiel purchased Atari from Warner, but Warner retained the “Atari Games” division sold to Namco.

Tramiel developed the Atari ST. Then in the 1996 the failure of the Atari Lynx handheld console and the Jaguar 64bit console brought Atari out of business and was eventually acquired by JTS Corporation for a short period and then by Hasbro

In 2000 the French software publisher Infogrames created Atari SA company*,* coming back to releasing games like Never Winter Nights (RPG) and V-Rally. Sometimes you see the Atari logo in the games released for Xbox and PlayStation: now Atari is an intellectual property holder, and no more hardware is produced.

Atari tried to capitalize its history announcing in 2017 the Atari VCS, hardware but the launch was delayed up to the end of 2019, and we are still waiting…. By the way, it is rather difficult to enter in the console videogames nowadays.

The Pong Console

Atari produced Pong as a coin-op game, then Atari decided to produce an home version.

Pong is a table tennis sports game featuring simple two-dimensional graphics.

Pong was the first commercially successful video game, which helped to establish the video game industry along with the first home console, the Magnavox Odyssey. The company released several sequels which built upon the original's gameplay by adding new features.

Pong was the first game developed by Atari.

After producing Computer Space, Bushnell decided to form a company to produce more games by licensing ideas to other companies.

Allan Alcorn created Pong as a training exercise assigned to him by Atari co-founder Nolan Bushnell. Prior to working at Atari, Allan Alcorn had no experience with video games.

To acclimate Alcorn to creating games, Bushnell gave him a project secretly meant to be a warm-up exercise.

The company announced Pong on 29 November 1972.

When the company did file for patents, complications delayed the process.

The Atari 2600 (1977)

Atari 2600. The top bezel of the cast included the switches for power, player difficulty switches, etc.
Atari 2600. The top bezel of the cast included the switches for power, player difficulty switches, etc.

Atari 2600 / Atari VCS

The Atari 2600, originally sold as the Atari Video Computer System (VCS) is a home video game console from Atari, Inc. Released on September 11, 1977, it is credited with popularizing the use of microprocessor-based hardware and games contained on ROM cartridges, a format first used with the Fairchild Channel F in 1976.

Atari 2600 Highlights

Ultimately, the consoles were shipped to retailers in November 1977.

Atari sold between 350,000 and 400,000 Atari VCS units during 1977, attributed to the delay in shipping the units and consumers' uncertainty about the console compared to the dedicated Pong consoles.

However, the VCS still had gained a killer application to sell the console, and it had suffered the loss of programmers David Crane, Bob Whitehead, Larry Kaplan, and Alan Miller, the company's “Fantastic Four”, who had programmed most of the successful VCS games to that point.

he four left Atari disgruntled over Warner's oversight of the company and treatment of programmers in 1978, and formed the firm Activision, which would give rise to third-party software for the VCS.

Atari attempted legal action to block sale of the Activision cartridges, but failed, allowing other third party game developers for the VCS to flourish.

As we see, third party games was very important to the success of these platform. In general the Company producing the console wants a strict control over the games, to ensure quality and to show sharolders it has a competitive advantage over competitions. Indie producers had always a tough life.

Initially, each VCS game fit into a 2K ROM

The Extra-Terrestrial and Pac-Man, are frequently blamed for contributing to the video game crash of 1983 (as we will see in the next chapters).

  1. Atari 2600 Hardware

    Atari 2600 deserve a detailed hardware description because it was the first home computer console sold in huge quantities. Also, it is the only console which survived to the video game crash of 1983, because it was very cheap to produce and keep going up to 1992!

    The Atari 2600's CPU is the MOS Technology 6507, stripped down version of the 6502 running at 1.19 MHz with only 13 memory-address instead of 16, so it was cheaper to produce.

    /As we see, the 6502 will be the dominant chip of the 8-bit computers of the '80. For instance, Microsoft Basic will be developed for this chip and sold to various company. So it is not a surprise the 6502 and variant are shared by Atari, Commodore and NES, even with variants./

    The designers of the Atari 2600 selected an inexpensive cartridge interface that had one fewer address than the 13 allowed by the 6507, further reducing the already limited addressable memory to 4 kiB (212 = 4096). This was believed to be sufficient as Combat was itself only 2 kiB.

    Later games get around this limitation with bank switching, up to the 32Kb limit.

    The console has only 128 bytes of RAM for scratch space, the call stack, and the state of the game world.

    For comparison, a PS4 has about 8*109 bytes of RAM!

    Programming was hard because the chip was able to buffer only one line at a time, ad strict timing was necessary to avoid a flickering image.

Intellivision 1979


The Intellivision is a home video game console released by Mattel Electronics in 1979. The name Intellivision is a portmanteau of “intelligent television”.

Intellivision Highlights

The name Intellivision is a portmanteau of “intelligent television”

In 2009, video game website IGN named the Intellivision the No

Mattel identified a new but expensive chipset from National Semiconductor and negotiated better pricing for a simpler design

Mattel Electronics would become a subsidiary in 1981

Before Mattel shifted manufacturing to Hong Kong, Mattel Intellivisions were manufactured by GTE Sylvania

Mattel formed its own software development group and began hiring programmers

In public, the programmers were referred to collectively as the Blue Sky Rangers

Mattel organized its games into networks: Major League Sports, Action, Strategy, Gaming, Children's Learning and later Space Action, and Arcade

Mattel Electronics' team of programmers was diverse in experience and talent, proving to be an advantage


Two tracks are read only for the software, and two tracks for user data

It uses the Intellivision's power supply

In the fall of 1981 design changes were finally implemented and the Keyboard Component was released at $600 in Seattle and New Orleans only

Mattel provided a full refund but without a receipt paid $550 for the Keyboard Component, $60 for the BASIC cartridge, and $30 for each cassette software

Today, very few of them still exist

Many of the units were dismantled for parts

In the fall of 1982, the LUCKI, now renamed the Entertainment Computer System (ECS), was presented at the annual sales meeting, officially ending the ill-fated keyboard component project

In the end a half-dozen software titles were released for the ECS; a few more were completed but not released

Mattel Electronics planned to use that connector for wireless hand controllers

Mattel Electronics built a state of the art voice processing lab to produce the phrases used in Intellivoice games

In the spring of 1983, Mattel introduced the Intellivision II

Otherwise the Intellivision II was promoted to be compatible with the original

Mattel secretly changed the Intellivision's internal ROM program (Exec) in an attempt to lock out 3rd party titles

Mattel Electronics provided 25% of revenue and 50% of operating income in fiscal 1982

Activision and Imagic began releasing games for the Intellivision, as did hardware rival Coleco

Mattel created “M Network” branded games for Atari's system

Still hiring continued, and optimism that the investment in software and hardware development will payoff

Amid the flurry of new hardware and software development, there was trouble for the Intellivision

In 1983 the price of home computers, particularly the Commodore 64, came down drastically to compete with video game system sales

The market became flooded with hardware and software, and retailers were ill-equipped to cope

The response was underwhelming

Amidst massive losses, top management was replaced

On February 4, 1984 Mattel sold the Intellivision business for $20 million

In 1983

Valeski found investors and purchased the rights to Intellivision, the games, and inventory from Mattel

They continued to supply the large toy stores and sold games through direct mail order

At first they sold the existing inventory of games and Intellivision II systems

When the inventory of games sold out they produced more, but without the Mattel name or unnecessary licenses on the printed materials

They continued to work on Intellivision, Colecovision, and other computer games

Also in 1987 INTV Corp released Dig Dug, purchased from Atari where the game was completed but not released in 1984

It is a modified Intellivision, the case molded in light beige with gold and blue trim

These compilation CDs play the original game code through emulators for MS-DOS, Windows, and Macintosh computers

Also in 1997 Intellivision Productions announced they would sell development tools allowing customers to program their own Intellivision games

Also in 1999, Activision released A Collection of Intellivision Classic Games for PlayStation

for the Nintendo DS including one never before released game, Blow Out

One includes 25 games the other ten

As such they look and play differently than Intellivision

Shark!, Skiing and Snafu

The number of Intellivision games that can be played effectively with contemporary game controllers is limited

It is a miniature sized Intellivision console with two original sized Intellivision controllers

As with many of the other Intellivision compilations, no games requiring third party licensing were included.

Apple ][ Computers (1977-1993)


Normally I refrain to talk about Apple II because it was not a computer for the “masses” as we will see. Anyway, Apple II is a very good example of the duo Steve Wozniak & Steve Jobs.

Steve Wozniak designed the Apple ][ and give Apple fuel to “Think different” and then produce the Steve Job's Macintosh.

Apple ][ is the humble system which you need to sell, to do great things.

So let's summarize why Apple ][ is damn important.

The Apple ][ is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak (Steve Jobs oversaw the development of the Apple II's foam-molded plastic case).

Figura 1 Apple ][ Figura 2 Apple ][ +

It was a long-selling product from 1977 to end of 1982 and sustained Apple revenue up to Machintosh success

Timeline of Apple II family models

From Wikipedia, https://en.wikipedia.org/wiki/Timeline_of_the_Apple_II_family

Commodore enters in the play

“Business is war, I don't believe in compromising, I believe in winning” - JackTramiel

CommodoreInternational Logo

Commodore International was an American home computer and electronics manufacturer founded by Jack Tramiel. Commodore International (CI), along with its subsidiary Commodore Business Machines (CBM), participated in the development of the home personal computer industry in the 1970s and 1980s.

CBM developed and marketed the world's best-selling desktop computer, the Commodore 64 (1982), and released its Amiga computer line in July

  1. With quarterly sales ending 1983 of $49 million (equivalent to

$106 million in 2018), Commodore was one of the world's largest personal computer manufacturers.

Commodore: the beginnings

The company that would become Commodore Business Machines, Inc. was founded in 1954 in Toronto as the Commodore Portable Typewriter Company by Polish-Jewish immigrant and Auschwitz survivor Jack Tramiel. By the late 1950s a wave of Japanese machines forced most North American typewriter companies to cease business, but Tramiel instead turned to adding machines.

In 1955, the company was formally incorporated as Commodore Business Machines, Inc. (CBM) in Canada. In 1962 Commodore went public on the New York Stock Exchange (NYSE), under the name of Commodore International Limited.

Commodore soon had a profitable calculator line and was one of the more popular brands in the early 1970s, producing both consumer as well as scientific/programmable calculators. However, in 1975, Texas Instruments, the main supplier of calculator parts, entered the market directly and put out a line of machines priced at less than Commodore's cost for the parts. Commodore obtained an infusion of cash from Gould, which Tramiel used beginning in 1976 to purchase several second-source chip suppliers, including MOS Technology, Inc., in order to assure his supply. He agreed to buy MOS, which was having troubles of its own, only on the condition that its chip designer Chuck Peddle join Commodore directly as head of engineering.

Through the 1970s Commodore also produced numerous peripherals and consumer electronic products such as the Chessmate, a chess computer based around a MOS 6504 chip, released in 1978.

In December 2007, when Tramiel was visiting the Computer History Museum in Mountain View, California, for the 25th anniversary of the Commodore 64, he was asked why he called his company Commodore. He said: "I wanted to call my company General, but there are so many Generals in the U.S.: General Electric, General Motors. Then I went to Admiral, but that was taken. So I wind up in Berlin, Germany, with my wife, and we were in a cab, and the cab made a short stop, and in front of us was an Opel Commodore." Tramiel gave this account in many interviews, but Opel's Commodore didn't debut until 1967, years after the company had been named.

Once Chuck Peddle had taken over engineering at Commodore, he convinced Jack Tramiel that calculators were already a dead end, and that they should turn their attention to home computers. Peddle packaged his single-board computer design in a metal case, initially with a keyboard using calculator keys, later with a full-travel QWERTY keyboard, monochrome monitor, and tape recorder for program and data storage, to produce the Commodore PET (Personal Electronic Transactor). From PET's 1977 debut, Commodore would be a computer company.

By 1980, Commodore was one of the three largest microcomputer companies, and the largest in the Common Market. The company had lost its early domestic-market sales leadership, however; by mid-1981 its US market share was less than 5%, and US computer magazines rarely discussed Commodore products. BYTE stated of the business computer market that "the lack of a marketing strategy by Commodore, as well as its past nonchalant attitude toward the encouragement and development of good software, has hurt its credibility, especially in comparison to the other systems on the market". The author of Programming the PET/CBM (1982) stated in its introduction that "CBM's product manuals are widely recognized to be unhelpful; this is one of the reasons for the existence of this book".

In the 1981 Commodore reemphasized the US market with the VIC-20, which was introduced at a cost of US$299 and sold in retail stores. Commodore bought aggressive advertisements featuring William Shatner asking consumers "Why buy just a video game?" The strategy worked and the VIC-20 became the first computer to ship more than one million units. A total of 2.5 million units were sold over the machine's lifetime and helped Commodore's sales to Canadian schools.

History of Commodore Computers

History of Commodore Computers3
- 1953: Jack Tramiel opens a typewriter repair shop in the Bronx, New York.
- 1954: Tramiel founds Commodore.
- 1955: Tramiel relocates to Toronto and becames the biggest manufacturer of low cost office furniture in Canada
- 197? Commodore manufactures calculators and digital watches, but gets killed by Texas Instruments.
- 1976: Commodore purchases MOS Technologies, an American maker of IC chips. MOS' senior engineer, Chuck Peddle was working on the 6502 micro processor. A popular 8 bit processor that soon would be used in machines like the Apple II, the Atari 800, the Commodore PET and 64.
- 1977: January - Commodore first shows a prototype PET computer at the Winter Consumer Electronics Show.
- 1977: June - Commodore shows its first production PET computers at the Summer Consumer Electronics Show.
- 1980: May - Commodore Business Machines introduces the CBM 8032 microcomputer, with 32KB RAM and an 80-column monochrome display.
- 1980: May - Commodore Business Machines introduces the CBM 8050 dual 5 1/4-inch floppy disk drive unit.
- 1980: Commodore Japan introduces the VIC-1001 (later called the VIC-20 in the USA).
- 1981: January - Commodore announces the VIC-20, for US$299. During its life, production peaks at 9,000 units per day.
- 1982: January - Commodore announces the Commodore 64 microcomputer, showing a prototype at the Winter CES, for US$600) for US$595.
- 1982: January - Commodore introduces the 16K SuperVIC.
- 1982: April - Commodore announces the B (700) and P (500) series of microcomputers, for US$1700-3000.
- 1982: September - Commodore Business Machines begins shipping the Commodore 64. Suggested retail price is US$595.
- 1982: Commodore releases the 1540 Single-Drive Floppy for the VIC-20.
- 1983: January - Commodore Business Machines begins selling the Commodore 64 through mass merchants, which drops the retail price to US$400.
- 1983: January - At the Winter CES, Commodore debuts the Commodore SX-100, a portable version of the Commodore 64, with bundled B/W screen, for US$995. Price with color screen and two drives is US$1295.
- 1983: January - At the Winter CES, Commodore demonstrates the HHC-4 (Hand-Held Computer). It features 24-character LCD screen with 4 KB RAM expandable to 16 KB. This was one of Commodore's pre-PET business products. Price is US$199.
- 1983: January - Commodore's sales of VIC-20s reaches 1,000,000.
- 1983: January - Commodore introduces the SX-64, the first color portable computer. Weight is 10.5 kg. It incorporates a 5-inch color monitor and one or two 5.25 inch floppy drive. Price is US$1600.
- 1983: April - Commodore drops dealer prices on the VIC-20, which allows it to drop below US$100 retail, the first color computer to hit that mark.
- 1983: April - Commodore offers a US$100 rebate on the purchase of a Commodore 64 on receipt of any computer or videogame unit.
- 1983: May - Commodore ships the Commodore Executive 64. It features 64KB RAM, detachable keyboard, 5-inch color monitor, 170KB floppy drive, for US$1000.
- 1983: June - Commodore drops the dealer price of the Commodore 64 to US$200, allowing the retail price to drop to US$200-230.
- 1983: June - At the Summer CES, Commodore shows the B128/256-80, formerly called P128. It has a monochrome monitor with 80-column display. They also show the Executive 64, formerly the Commodore SX-100. It has a 6-inch color monitor and is priced at US$995.
- 1983: Commodore debuts the Exactron Stringy Floppy, a high-speed cassette-based data storage device.
- 1984: January - Jack Tramiel,President of Commodore International, has a disagreement with the major share holder, Irvin Gould. Tramiel leaves the company and a few months later buys Atari.
- 1984: January - At the Winter CES, Commodore shows the SX-64, formerly called Executive 64. It now includes a 5-inch monitor, and one 170KB 5 1/4 disk drive, for US$995.
- 1984: January - Commodore announces that during 1983, Commodore sold US$1 billion worth of computers, the first personal computer company to do so.
- 1984: June - Commodore announces the Commodore 16. Former name was TED-16 and is expected to sell for around US$100, and marketed as "The Learning Machine".
- 1984: June - Commodore announces the Commodore Plus/4, formerly called the Commodore 264. It will now feature four built-in programs, not just one. Price should be around US$300.
- 1984: August - Commodore purchases Amiga Corporation.
- 1984: Commodore stops manufacturing the VIC-20.
- 1985: January - Commodore unveils the Commodore 128 Personal Computer. It functions as three computers in one: a complete Commodore 64, a CP/M mode, and a new 128KB mode.
- 1985: January - Commodore announces the 1571 Disk Drive, for the Commodore 128.
- 1985: July - Commodore unveils the new Amiga 1000 in New York, for US$1300.
- 1985: Commodore stops production of the Commodore 64 several times during the year, restarting each time based on public demand.
- 1986: Commodore releases Transformer software for the Amiga, which, along with the Commodore 1020 5 1/4-inch disk drive, provides limited MS-DOS compatibility.
- 1987: January - Commodore announces the Amiga 500 and the Amiga 2000.
- 1987: January - Commodore debuts the Commodore 128D in the North American market.
- 1988: December - Commodore announces the A2286D Bridgeboard for the Amiga 2000. The A2286D contains an 8-MHz Intel 80286 and a 1.2MB 5 1/4-inch disk drive.
- 1988: Commodore introduces the Amiga 2000HD and the Amiga 2500.
- 1989: January - Commodore announces that 1 million Amiga computers have been sold.
- 1989: November - Commodore announces the Amiga 2500/30. It is essentially an Amiga 2000 with a 2630 Accelerator Board (25-MHz 68030 and 68882 math coprocessor).
- 1990: April - Commodore offers Amiga 1000 owners US$1000 to trade in their Amiga on a new Amiga 2000.
- 1990: June - Commodore ships the Amiga A3000 computer.
- 1990: September - NewTek ships the Video Toaster, a hardware/software video effects tool for the Commodore Amiga 2000, for US$1600.
- 1990: Commodore announces the Amiga 3000. Prices start at US$4100 with a monitor.
- 1991: January - Commodore releases the CDTV package. It features a CD-ROM player integrated with a 7.16-MHz 68000-based Amiga 500. List price is US$1000.
- 1992: Commodore introduces the Amiga 600 for a base price of $500.
- 1992: September - Commodore introduces the Amiga 4000.
- 1992: December - Commodore introduces the Amiga 1200.
- 1994: Commodore International and Commodore Electronics (two of the many international components of Commodore Business Machines) file for voluntary liquidation.
- 1995: April - At an auction in New York, ESCOM buys all rights, properties, and technologies of Commodore.
- 1997: Gateway buys bankrupt Amiga.

Commodore VIC-20: Why buy just a video game? (1980)


The VIC-20 is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore's first personal computer, the PET.

The VIC-20 was the first computer of any description to sell one million units.

The VIC-20 has been described as "one of the first anti-spectatorial, non-esoteric computers by design…no longer relegated to hobbyist/enthusiasts or those with money, the computer Commodore developed was the computer of the future."

The VIC-20 was intended to be more economical than the PET computer. It was equipped with 5KB of static RAM and used the same MOS 6502 CPU as the PET. 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 could not find a market for the chip.

As the Apple II gained momentum with the advent of VisiCalc in 1979, Jack Tramiel wanted a product 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, mostly because it required an 80-column character display which in turn required the MOS Technology 6564 chip. However, the chip could not be used in the TOI 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. With the TOI unfinished, when Jack Tramiel was shown the MicroPET prototype, he immediately said he wanted it to be finished and ordered it to be mass-produced following a limited demonstration at the CES.

/As the new decade began, the price of computer hardware was dropping and Tramiel saw an emerging market for low-price computers that could be sold at retail stores to relative novices rather than professionals or people with an electronics or programming background./ The personal computer market up to this point had sold primarily through mail order or authorized dealers, the sole exception being Radio Shack, who had their own stores as a distribution network.

The 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 a ROM cartridge port. The serial IEEE-488-derivative CBM-488 interface was designed by Glen Stark. It served several purposes, including costing substantially less than the IEE-488 interface on the PET, using smaller cables and connectors that allowed for a more compact case design, and also complying with newly-imposed FCC regulations on RFI emissions by home electronics (the PET was certified as Class B office equipment which had less stringent RFI requirements).

Some features, like the memory add-in board, were designed by Bill Seiler. Altogether, the VIC 20 development team consisted of five people, who referred to themselves as the VIC Commandos. According to one of the development team, Neil Harris, "[W]e couldn't get any cooperation from the rest of the company who thought we were jokers because we were working late, about an hour after everyone else had left the building. We'd swipe whatever equipment we needed to get our jobs done. There was no other way to get the work done! […] they'd discover it was missing and they would just order more stuff from the warehouse, so everybody had what they needed to do their work." At the time, Commodore had a surplus of 1 kbitÎ4 SRAM chips, so Tramiel decided that these should be used in the new computer. The end result was 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.

The amount of memory on the VIC-20's system board was very small even for 1981 standards.

This is evident if you think how the Super Expander cartridge (below) was minded. It not only added new BASIC commands but also enough RAM to use a “bitmap” mode.

While newer PETs had the upgraded BASIC 4.0, which had disk commands and improved garbage collection, the VIC-20 reverted to the 8KB BASIC 2.0 used on earlier PETs as part of another of the design team's goals, which was limiting the system ROMs to only 20KB. Since Commodore's BASIC had been designed for the PET which had only limited audiovisual capabilities, there were no dedicated sound or graphics features, thus VIC-20 programmers had to use large numbers of POKE and PEEK statements for this. This was in contrast to the computer's main competitors, the Atari 400 and TRS-80 Color Computer, both of which had full-featured BASICs with support for the machines' sound and graphics hardware. Supplying a more limited BASIC in the VIC-20 would keep the price low and the user could purchase a BASIC extender separately if he desired sound or graphics commands.

While the TRS-80 Color Computer and Atari 400 had only RF video output, the VIC-20 instead had composite output, which provided a sharper, cleaner picture if a dedicated monitor was used. An external RF modulator was necessary to use the computer with a TV set, and had not been included internally so as to comply with FCC regulations (Commodore lobbied for and succeeded in getting them relaxed slightly by 1982, so the C/64 had an RF modulator built in).

VIC-20s went through several variations in their three and a half years of production.

The Japan's VIC-1001

In April 1980, at a meeting of general managers outside London, Jack Tramiel declared that he wanted a low-cost 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 UK's top marketing executive. Then, the project was given to Commodore Japan; an engineering team led by Yash Terakura created the VIC-1001 for the Japanese market. The VIC-20 was marketed in Japan as VIC-1001 before VIC-20 was introduced to the US.

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 (inspired by competing Japanese computers), full-size typewriter-style keys, and built-in RS-232. Tomczyk insisted on "user-friendliness" as the prime directive for the new computer, to engineer Yash Terakura (who was also a friend), and proposed a retail price of US$299.95. He recruited a marketing team and a small group of computer enthusiasts, and worked closely with colleagues in the UK and Japan to create colorful packaging, user manuals, and the first wave of software programs (mostly games and home applications).

Scott Adams4 was contracted to provide a series of text adventure games. With help from a Commodore engineer who came to Longwood, Florida to assist in the effort, five of Adams's Adventure International game series were ported to the VIC. They got around the limited memory of VIC-20 by having the 16 KB games reside in a ROM cartridge instead of being loaded into main memory via.

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.

As we will see, this marketing idea will be a game changer. It helped to popularize 8-bit computers, even if these computers will be most of the time “game console” disguised as computers.

Commodore took out advertisements featuring actor William Shatner (of Star Trek fame) as its spokesman, asking: "Why buy just a video game?" and describing it as "The Wonder Computer of the 1980s". Television personality Henry Morgan (best known as a panelist on the TV game show I've Got a Secret) became the commentator in a series of Commodore product ads.

The VIC-20 had 5KB of RAM, of which only 3.5KB remained available on startup (exactly 3583 bytes). This is roughly equivalent to the words and spaces on one sheet of typing paper, meeting a design goal of the machine. The computer was expandable up to 40KB with an add-on memory cartridge (a maximum of 27.5KB was usable for BASIC).

The "20" in the computer's name was widely assumed to refer to the text width of the screen (although in fact the VIC-20 has 22-column text, not

  1. or that it referred to the combined size of the system ROMs (8áKB

BASIC+8áKB KERNAL+4áKB character ROM).

/Bob Yannes claimed that "20" meant nothing in particular and "We simply picked '20' because it seemed like a friendly number and the computer's marketing slogan was 'The Friendly Computer'. I felt it balanced things out a bit since 'Vic' sounded like the name of a truck driver."/

In 1981, Tomczyk contracted with an outside engineering group to develop a direct-connect modem-on-a-cartridge (the VICModem), which at US$99 became the first modem priced under US$100. The VICModem was also the first modem to sell over 1 million units. VICModem was packaged with US$197.50 worth of free telecomputing services from The Source, CompuServe and Dow Jones. Tomczyk also created a SIG called the Commodore Information Network to enable users to exchange information and take some of the pressure off of Customer Support inquiries, which were straining Commodore's lean organization.

The VIC-20 was the best-selling computer of 1982, with 800,000 machines sold.

One million units had been sold by the end of the first full year of production; at one point, 9,000 units a day were being produced.

With the introduction of Commodore 64 in the 1982, VIC-20 destiny was signed.

Sales of the C/64 were slow at first due to reliability problems and lack of software. But by the middle of 1983, sales of the C/64 took off resulting in plunging sales for the VIC-20. In order to try and staunch the sales decline, by mid-1983 the computer had become widely available for under $90. As sales of the computer continued to decline, the VIC-20 was quietly discontinued in January 1985. Perhaps the last new commercially available VIC-20 peripheral was the VIC-Talker, a speech synthesizer


The VIC-20's BASIC is compatible with the PET's, and the Datasette format is the same. Before the computer's release, a Commodore executive promised that it would have "enough additional documentation to enable an experienced programmer/hobbyist to get inside and let his imagination work". Compute! favorably contrasted the company's encouragement of "cottage industry software developers" to Texas Instruments discouraging third-party software.

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.

The VIC had a sizable library of public domain and freeware software. This software was distributed via online services such as CompuServe, BBSs, as well as offline by mail order and by user groups. Several computer magazines sold on newsstands, such as Compute!, Family Computing, RUN, Ahoy!, and the CBM-produced Commodore Power Play, offered programming tips and type-in programs for the VIC-20.

An estimated 300 commercial titles were available on cartridge and another 500+ were available on tape. Games on cartridge include Gorf, Radar Rat Race, Sargon II Chess, and Jupiter Lander. A handful of disk applications were released.

The VIC's low cost led to it being used by the Fort Pierce, Florida Utilities Authority to measure the input and output of two of their generators and display the results on monitors throughout the plant. The utility was able to purchase multiple VIC and C/64 systems for the cost of one IBM PC compatible.

The Super Expander

The Super Expander cartridge added BASIC commands supporting such a graphics mode using a resolution of 160Î160 pixels. 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.

Vic20 Specification

The VIC-20 had card edge connectors for program/expansion cartridges and a tape drive (PET-standard Datassette). It came with 5 KB RAM, but 1.5 KB of this was 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, only 3583 bytes of BASIC program memory for code and variables was actually available to the user of an unexpanded machine.

A funny story is about the “KERNAL” world. The name should be KERNEL but apparently was misspelled:

According to early Commodore myth, and reported by writer/programmer Jim Butterfield among others, the "word" KERNAL is an acronym standing for *K*eyboard *E*ntry *R*ead, *N*etwork, And *L*ink, which in fact makes good sense considering its role.5

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

Importantly, like most video game consoles and many computers at the time the VIC had a ROM 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 attached at a time. Cartridge software ranged from 4 to 16 KB in size, although the latter was uncommon due to its cost and only larger software houses produced 16 KB cartridges. 00 The graphics capabilities of the VIC chip (6560/6561) were limited but flexible. At startup the screen showed 176x184 pixels, with a fixed-color border to the edges of the screen. Since a PAL or NTSC 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 up to 27 columns, but the characters would soon run out the sides of the monitor at about 25 columns. Just as on the PET, two different 256 character sets were included, the uppercase/graphics character set and the upper/lowercase set, and reverse video versions of both. Normally, the VIC-20 was operated in high-resolution mode whereby each character was 8x8 pixels in size and used one color. A lower-resolution multicolor mode could also be used with 4x8 characters and three colors each, but it was not used as often due to its extreme blockiness.

The VIC chip did not support sprites.

Bitmap mode “trick”

The VIC chip did not support a true bitmap mode, but programmers could define their own custom character set. It was possible to get a fully addressable screen, although slightly smaller than normal, by filling the screen with a sequence of different double-height characters, then turning on the pixels selectively inside the RAM-based character definitions. The Super Expander cartridge added BASIC commands supporting such a graphics mode using a resolution of 160x160 pixels. 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 had readable scan-line counters but could not generate interrupts based on the scan position (as the VIC-II chip could). However, the two VIA timer chips could be tricked into generating interrupts at specific screen locations. This could be accomplished by setting up the timers after a position had been established by repetitive reading of the scan-line counter, and letting them run the exact number of cycles that pass by during one full screen update. Thus it was possible but difficult to mix graphics with text above or below it, or to have two different background and border colors, or to use more than 200 characters for the pseudo-high-resolution mode.6 The VIC chip could also process a light pen signal (a light pen input was provided on the DE-9 joystick connector) but few of those ever appeared on the market.

The VIC chip output composite video; Commodore did not include an RF modulator inside the computer's case because of FCC regulations. It could either be attached to a dedicated monitor or a TV set using the external modulator included with the computer.

The VIC chip had three pulse wave sound generators. Each had a range of three octaves, and the generators were located on the scale about an octave apart, giving a total range of about five octaves. In addition, there was a white noise generator. There was only one volume control, and the output was in mono.

Because the VIC had only 5K RAM, the VIC-20's RAM was expandable through the cartridge port via a Super Expander Cartridge (or simply, RAM Expander). RAM cartridges were available in several sizes: 3 KB (with or without an included BASIC extension ROM), 8 KB, 16 KB, 32 KB and 64 KB, the latter two only from third-party vendors. /The internal memory map was dramatically reorganized with the addition of each size cartridge, leading to a situation where some programs would only work if the right amount of memory was present/ (to cater to this, the 32 KB cartridges had switches, and the 64áKB cartridges had software setups, allowing the RAM to be enabled in user-selectable memory blocks).

Since the VIC-20 was designed to use SRAM rather than DRAM, the system board had no provisions for RAM refresh. Memory expansion cartridges may in practice use either type; however, DRAM-based expanders had to contain their own circuitry to refresh the RAM and multiplex the data/address bus, and one possible reason for the oversized VIC-20 cartridge PCBs may have been to provide room for DRAM infrastructure.

Commodore's official RAM expansion cartridges were only available up to a maximum of 16KB worth of additional memory, but third party cartridges could provide up to 64áKB and sometimes included DIP switches to map the additional RAM to user-selectable address space.

Describing it as "an astounding machine for the price", Compute! in 1981 expected that the VIC-20 would be popular in classrooms and homes with small children, with "excellent graphic and sound capabilities". While predicting that the 22-column screen was "too small to support any but the most rudimentary business applications" the magazine observed that "at a price of $299, that is hardly the point", stating that "the VIC will provide very stiff competition to the TRS-80 Color Computer" and "is a much more valuable computer literacy tool than" other products like the TRS-80 Pocket Computer. Compute! concluded that "VIC will create its own market, and it will be a big one". While also noting the small screen size and RAM, BYTE stated that the VIC 20 was "unexcelled as low-cost, consumer-oriented computer. Even with some of its limitations … it makes an impressive showing against … the Apple II, the Radio Shack TRS-80, and the Atari 800". The magazine praised the price ("Looking at a picture … might cause you to think $600 would be a fair price … But it does not cost $600 the VIC 20 retails for $299.95"), keyboard ("the equal of any personal-computer keyboard in both appearance and performance. This is a remarkable achievement, almost unbelievable considering the price of the entire unit"), graphics, documentation, and ease of software development with the KERNAL.

The VIC-20 could be hooked into external electronic circuitry via joystick port, the so-called "user port," or the memory expansion cartridge port, 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, but an extremely reliable digital tape storage system (using audio cassette tapes); the VIC-1540 disk drive was released in 1981.

Recent software releases such as clones of Frogger (2007 release) and Berzerk (2010 release) have gameplay, graphics, and sound (including voice synthesis in Berzerk) that are comparable to the original arcade machines. A port of Doom, a 1993 game popularized on much more powerful platforms, became available for the VIC-20 in 2013.

The VIC-20 was called VC-20 in Germany because the pronunciation of VIC with a German accent as well as its codename Vixen both sound like German curse words. The term VC was marketed as though it was an abbreviation of VolksComputer ("people's computer", similar to Volkswagen, Volksempfõnger, etc.)

BYTE in 1983 published a series of technical articles about the VIC-20.

In 1982, Commodore introduced the Commodore 64 as the successor to the VIC-20.

VIC20 Legacy

VIC 20 has tiny memory, but a full featured keyboard and a huge software library, mostly of games.

The Super Expander should be developed and packed with the computer, because would have balanced it lack of power (mostly memory and graphic).

From the Vic-20 Commodore take the VIC-I chip and started developing two different evolution:

Of the two, the SID is a bit more more innovative in our humble opinion, but together with a pack of RAM the resulting computer will be very impressive, as we shall see.

So, we can say the C/64 is the Vic20 legacy: the two machine shares the same chip, the same BASIC and the same plastic shell, but are quite different in the inside.

Commodore 64 (1982)



The Commodore 64, also known as the C/64 or the CBM 64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, in Las Vegas, January 7-10, 1982). It has been listed in the Guinness World Records as the highest-selling single computer model of all time, with independent estimates placing the number sold between 10 and 17 million units.

Introducing the best selling computer ever

It is very difficult to talk about the C/64 because everything has been already said.

The machine was ahead of time for its custom chips, and the amount of RAM.

Lack of the built-in software was compensated with a good manual and a very huge set of third-party software.

As we will see, Commodore tried to offer better Basic for C/16, Plus/4 and Commodore 128, but that three computers would not be able to take over from where C/64 left.

/Early C/64 advertisements boasted, "You can't buy a better computer at twice the price." TI responded by cutting prices on its TI-99/4A, which had been introduced in 1981. Soon there was an all-out price war involving Commodore, TI, Atari, and practically every vendor other than Apple Computer…/

A better TOI

According to Wikipedia8 during the 1981

[…]Robert 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. […] They proposed to Commodore CEO Jack Tramiel a true low-cost sequel to the VIC-20. Tramiel dictated that the machine should have 64 KB of random-access memory (RAM). Although 64-Kbit dynamic random-access memory (DRAM) chips cost over US$100 (equivalent to $232.95 in 2018) at the time, he knew that DRAM prices were falling, and would drop to an acceptable level before full production was reached. The team was able to quickly design the computer because, unlike most other home-computer companies, Commodore had its own semiconductor fab to produce test chips; because the fab was not running at full capacity, development costs were part of existing corporate overhead. […]

The product was code named the VIC-40 as the successor to the popular VIC-20. The team that constructed it consisted of Yash Terakura, Shiraz Shivji, Bob Russell, Bob Yannes and David A. Ziembicki.


When the product was to be presented, the VIC-40 product was renamed C/64.


The C/64 uses an 8-bit MOS Technology 6510 microprocessor. This is a close derivative of the 6502 with an added 6-bit internal I/O port that in the C/64 is used for two purposes: to bank-switch the machine's read-only memory (ROM) in and out of the processor's address space, and to operate the “datasette” tape recorder. The C/64 has 64 KB of RAM, of which 1024 bytes are color RAM for text mode and 38 KB are available to built-in Commodore BASIC 2.0 on startup. There is 20 KB of ROM, made up of the BASIC interpreter, the Kernal, and the character ROM.

65536 bytes of memory

Memory is a huge success factor of C/64. On that time, C/64 was the only one with 64Kb of RAM, which was the maximum RAM you can use with the MOS

Apple ][ for example could be expanded up to 48Kb, because some ROM was needed for the BASIC and the operating system.

A clever idea was to add 64KB anyway, using “bank switching” to be able to show/hide kernel and Basic V2.

So, in theory, a software house could produce a full-blown operating system for the C/64 (like GEOS64 will do). We stress this point because we think it will be a success factor for the high C/64 longevity.


The graphics chip, VIC-II, features 16 colors, eight hardware sprites per scanline scrolling capabilities, and two bitmap graphics modes. The standard text mode features 40 columns, like most Commodore PET models.

The C/64 has a resolution of 320 x 200 pixels, consisting of a 40 x 25 grid of 8 x 8 character blocks.

There are two colour modes, high resolution, with two colours available per character block (one foreground and one background) and multicolour with four colours per character block (three foreground and one background). In multicolour mode, attributes are shared between pixel pairs, so the effective visible resolution is 160 x 200 pixels. This is necessary since only 16 kB of memory is available for the VIC-II video processor.

Hardware sprites.
A sprite is a movable character which moves over an area of the screen, draws over the background and then redraws it after it moves. Note this is very different to character block animation, where you are just flipping character blocks. On the C/64, the VIC II video processor handles most of the legwork in sprite emulation, the programmer simply defines the sprite and where they want it to go. The C/64 has two types of sprites, respecting their color mode limitations. Hires sprites have one color (one background and one foreground), and multicolor sprites three (one background and three foreground). Color modes can be split or windowed on a single screen. Sprites can be doubled in size vertically and horizontally up to four times their size, but the pixel attributes are the same - the pixels become "fatter".

Sprites can move with glassy smoothness in front of and behind screen characters and other sprites.

Programmers will find out a way to show more than 8 sprint on the screen, keeping the limit of 8 sprites per scan line.

For more information on Sprite multiplexing refer for instance at




The Sound Interface Device (SID)

Figure 2 The Sound Interface Device Chip (SID)

The SID chip has three channels, each with its own ADSR envelope generator and filter capabilities. Ring modulation makes use of channel N°3, to work with the other two channels. Bob Yannes developed the SID chip and later co-founded 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 has become a hit of its own among C/64 users.

Well-known composers and programmers of game music on the C/64 are Rob Hubbard, Jeroen Tel, David Whittaker, Chris Hülsbeck, Ben Daglish, Martin Galway, Kjell Nordbø and David Dunn among many others.

Due to the chip's three channels, chords are often played as arpeggios, coining the C/64's characteristic lively sound. It was also possible to continuously update the master volume with sampled data to enable the playback of 4-bit digitized audio. As of 2008, it became possible to play four channel 8-bit audio samples, 2 SID channels and still use filtering.9

There are two versions of the SID chip: the 6581 and the 8580. The MOS Technology 6581 was used in the original ("breadbox") C64s, the early versions of the 64C, and the Commodore 128. The 6581 was replaced with the MOS Technology 8580 in 1987. While the 6581 sound quality is a little crisper and many Commodore 64 fans say they prefer its sound, it lacks some versatility available in the 8580 – for example, the 8580 can mix all available waveforms on each channel, whereas the 6581 can only mix waveforms in a channel in a much more limited fashion. The main difference between the 6581 and the 8580 is the supply voltage. The 6581 uses a 12 volt supply—the 8580, a 9 volt supply. A modification can be made to use the 6581 in a newer 64C board (which uses the 9 volt chip). The SID chip's distinctive sound has allowed it to retain a following long after its host computer was discontinued. A number of audio enthusiasts and companies have designed SID-based products as add-ons for the C/64, x86 PCs, and standalone or Musical Instrument Digital Interface (MIDI) music devices such as the Elektron SidStation. These devices use chips taken from excess stock, or removed from used computers. In 2007, Timbaland's extensive use of the SidStation led to the plagiarism controversy for "Block Party" and "Do It" (written for Nelly Furtado).

Commodore 64 Marketing

*Commodore sold the C/64 not only through its network of authorized dealers, but also through department stores, discount stores, toy stores and college bookstores.*

The C/64 had a built-in RF modulator and thus could be plugged into any television set. This allowed it (like its predecessor, the VIC-20) to compete directly against video game consoles such as the Atari 2600.

Tramiel placed a highly aggressive price of just $595 on the device (worth $1,477 in 2016) […]

It should be noted that Commodore tried on a couple of occasions to discontinue the C/64 in favour of more expensive computers such as the Commodore 128, but demand for the C/64 remained stubbornly strong. In 1986, Commodore did introduce the 64C, a redesigned C/64.10

Aggressive pricing of the C/64 is considered to have been a major catalyst in the North American video game crash of 1983.

For instance, in January 1983, Commodore offered a $100 rebate in the United States on the purchase of a C/64 to anyone that traded in another video game console or computer. To take advantage of this rebate, some mail-order dealers and retailers offered a Timex Sinclair 1000 for as little as $10 with purchase of a C/64. This deal meant that the consumer could send the TS1000 to Commodore, collect the rebate, and pocket the difference.

Commodore's tactics soon led to a price war with the major home computer manufacturers

Commodore dropped the C/64's list price by $200 within two months after its release.

At one point, the company was selling as many C64s as all computers sold by the rest of the industry combined.

Commodore sold about one million C64s in 1985 and a total of 3.5 million by mid-1986.

Price Drop Graph


To better understand the graph, two important fact must be take into account:

  1. 1983 there was the Video game crash, and C/64 price was dropped three times, from $400,00 to $200,00

  2. In the 1985 Commodore tried to stop C/64 production with little success, because demand was high. In the next year the Commodore 64C was produced, at $150

By the way Commodore 64C was identical to original C/64 but was a lot more cheap to produce. Keep in mind C/128 was the 1985 computer, with a C/64 compatibility mode: nerveless, customers demand C/64!

How many Commodore 64 computers were really sold?

In the article “How many Commodore 64 computers were really sold?”11 Michael Steil had a nice graph answering to this question with a very deep analysis. To make it short, the correct numbers seems around 12.5M units.

Please note the steady curve from 1985 up to 1990!

Software Built-in

As is common for home computers of the early 1980s, the C/64 comes with a BASIC interpreter, in ROM

Commodore BASIC 2.0 is used instead of the more advanced BASIC 4.0 from the PET series since C/64 users were not expected to need the disk-oriented enhancements of BASIC 4.0

BasicV2 Funny story: when Bill gates was forced to not get its


Microsoft is very famous because Bill Gates worked hard to license its product on a royalties-based schema instead of a simpler “perpetual license” one.

So it is funny to know /Commodore licensed BASIC from Microsoft on a "pay once, no royalties" basis after Jack Tramiel turned down Bill Gates' offer of a $3 per unit fee, stating, "I'm already married," and would pay no more than $25,000 for a perpetual license./12

Basic V2 was used in PET in the 1977, so this story is dated around that years.

Also, considering C/64 will sell over 12 million of units, the missed fee was a very bad deal for Microsoft. Anyway on that years was reported Microsoft needs funding, so Tramiel won.

C/64 Memory map

There is 20 KB of ROM, made up of the BASIC interpreter, the Kernal, and the character ROM

As the processor could only address 64 KB at a time, the ROM was mapped into memory, and only 38,911 bytes of RAM (plus 4KB in between the ROMs) were available at startup.

Via bank switching on location 0 you could see the entire RAM.

RAM underneath the system ROMs can be written to, but not read back without swapping out the ROMs. Also, by disabling I/O, $D000 -$DFFF becomes free RAM,

C/64 Software

C/64 Software collection is huge and impressive

Simons' BASIC

Simons' BASIC

Simons' BASIC was an extension to BASIC 2.0 for the Commodore 64 home computer. Written by British programmer David Simons in 1983, who was then just 16 years old at the time, it was distributed by Commodore in cartridge format. .

  1. Simons's BASIC Highlights

    A further extension was also written by Simons and released by Commodore on floppy disk and tape as Simons' Basic Extension

    This software is also known as Simons' Basic 2.

Geos 64

GEOS (Graphic Environment Operating System) was an operating system from Berkeley Softworks (later GeoWorks). Originally designed for the Commodore 64 with its version being released in 1986, enhanced versions of GEOS later became available in 1987 for the Commodore 128 and in 1988 for the Apple II family of computers.13

Geos64 was very impressive but painful slow, even if it provided a nice turbo disk to speed up drive operations. It offered a semi-professional set of tool like GeoWrite and GeoPaint

  1. Geos64 References

    1. Geos 64 original disks http://www.cbmfiles.com/geos/index.php

    2. Geos 64 source code at https://github.com/mist64/geos

C/64 Legacy




From VICE website:

VICE is a program that runs on a Unix, MS-DOS, Win32, OS/2, BeOS, QNX 4.x, QNX 6.x, Amiga, Syllable or Mac OS X machine and executes programs intended for the old 8-bit computers. The current version emulates the C64, the C64DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610/C510). An extra emulator is provided for C64 expanded with the CMD SuperCPU.

VICE is free software, released under the GNU General Public License.

VICE is still developed (last release is of December 2019) with features like

and so on.

It is the de-facto standard nowadays, at least for no-c/64 machine. Remember c/64 has plenty of emulators so far.

VICE Highlights

VICE feature a very rich command line you can use for configure every aspect of the emulation.


reSID is a C++ library containing a complete emulation of the SID chip.

It is a reverse engineered software emulation of the MOS6581 SID (Sound Interface Device) chip programmed by Dag Lem.
reSID is free software, published under the GNU General Public License.


Hoxs64 is a Windows10 C/64-only emulator with very good precision and a nice monitor debugger (see below).
Its source code is hosted at https://github.com/davidhorrocks/hoxs64/tree/master/hoxs64 and it is actively developed (last version was released on April 2019).

  1. Features

    • Cycle based CPU, CIA, VIC and SID.

    • 1541 Disk drive.

    • Tape deck.

    • Full screen mode.

    • Configurable keyboard and joystick.

    • D64 G64 P64 FDI TAP PRG P00 T64 file support.


Shareware & nice, you can try it before buy


  1. http://www.zimmers.net/anonftp/pub/cbm/crossplatform/emulators/resid/index.html

  2. https://en.wikipedia.org/wiki/ReSID

Demo Scene: “A Mind Is Born” the 256 byte demo (April 2017)

Making a demo in just 256 bytes would be a formidable challenge regardless of platform. A Mind Is Born is my attempt to do it on the Commodore 64. In the absence of an actual 256-byte compo, it was submitted to the Oldskool 4K Intro compo at Revision 2017, where it ended up on 1st place.

From https://linusakesson.net/scene/a-mind-is-born/

The demo is not very nice to see, but it is done only in 256 bytes:

The author explain the code, which is very dense by the way

80 Columns Text on the Commodore 64 (July 2017)

The text screen of the Commodore 64 has a resolution of 40 by 25 characters, based on the hardware text mode of the VIC-II video chip. This is a step up from the VIC-20's 22 characters per line, but since computers in the professional segment (Commodore PET 8000 series, CP/M, MS-DOS) usually had 80 columns, several solutions – both hardware and software – exist to allow 80 columns on a C/64 as well. Let's look at how this is done in software! At the end of this article, I present a fast and full-featured open source implementation with several different character sets.

From https://www.pagetable.com/?p=901

Note: this mode is hard to read, anyway is funny to note on which extent you can push your C/64 considering its age!

Super Mario on C/64 (April 2018)

After 7 years of development…

This is a Commodore 64 port of the 1985 game SUPER MARIO BROS. for the Famicom and Nintendo Entertainment System. It contains the original version that was released in Japan and United States, as well as the European version. It also detects and supports a handful of turbo functionalities, and has 2 SID support14.

This version took about 7 years to be completed by ZeroPaige, and was sued by Nintendo after a while.

It was supposed to be impossible to port, because the C/64 lack NES graphic and sound capabilities, but shared the same CPU of the original game.

I reported this game to show how even in 2019, after 37 years, C/64 is still used!

Retro Games: The C64 on 2019

On December 2019 TheC64 was produced by RetroGames.


The computer is a C/64 replica, sold at over 100€ only in Europe and UK. The8Bit guy made a nice review, noting it seems a Vic20 case replica (the C/64 case was a bit taller)

The case is quite empty, because the entire computer is emulated via an ARM-based board (possibly a Raspberry PI-like).

The software seems a modified version of VICE but the source are omitted.

Anyway the user manual is very well written, and enable the use of a very huge set of feature. For instance:

THEC64 locks to the HDMI rate of exactly 50 Hz or 60 Hz depending on the Video output setting, so that it produces super-smooth and tear-free graphics when running programs on a modern HD display.

Is it worth the price?

Difficult to say. The entire case is cheap, the keyboard is a membrane one, and no expansion ports are provided. So you cannot plug old cartige in this C/64. But the emulation seems okey.

The game changer should be the keyboard, but it is not like an old mechanical one.

Also the full user manual is NOT provided, only a "quickstart". You must download it. And this is a pity, because the old C/64 provided a very good manual.

A good retail price should be around 50-60€ in our humble opinion, or around 80 with a nice printed manual and at least.

RasperryPI cheap alternatives

You can try VICE also on a Raspberry PI via Combian distribution, made by an Italian guy, and there are plenty of other ways to do it.

The video game crash of 1983

Figure 3 PacMan Arcade (coin op) version

The video game crash of 1983 was a large-scale recession in the video game industry that occurred from 1983 to 1985, primarily in America. The crash was attributed to several factors, including market saturation in the number of game consoles and available games, and fading interest in console games in favor of personal computers.

The reason was two:

  1. A over saturation in the video game console market. By 1983, gamers had dozens of console choices to pick from.
    Let's consider this picture, to understand how much different console was on the market:
Over saturation
Over saturation
  1. After the success the video game industry experienced in the late 70's and early 80's, many companies were rushing to produce video games as quickly as possible.
    Console makers had lost control of what games were being developed for their platforms.
    So the market was flooded with games, often low quality one

This trend was amplified by two big bad games produced by Atari: E.T. the Extra-Terrestrial (based on Spielberg's film) and the Pac-Man port.

E.T. was produced in a very short time, and the overall game was bugged and not funny:

The team making E.T. was famously only given six weeks to develop, test, and market the game before it was shipped out for the holiday season. The video game they produced had little to do with the actual movie and was an immediate failure.
In September 1983, Atari discreetly buried much of this excess stock, as well as unsold stock of earlier games, in a landfill near Alamogordo, New Mexico, though Atari did not comment about their activity at the time.

The market shrink from $3.2 billion to 100 million, and a lot of company went bankrupt

Figure 4 Video Game Crash15

The end of the crash allowed Commodore to raise the price of the C/64 for the first time upon the June 1986 introduction of the Commodore 64C—a Commodore 64 redesigned for lower cost of manufacture—which Compute! cited as the end of the home-computer price war.

As we see above, the three-times C/64 price drops of 1983 could be considered one of the imploding factors too.

PacMan port was a failure because only two ghosts was present, and the game was too ugly compared to the coin-op version. The same could be said for E.T. even for the Atari 2600 low-standards.

Figure 5 Atari's E.T ugly Game

Figure 6 1980 Atari's PacMan port

The NES, Nintendo Entertainment System (1985)

"Atari collapsed because they gave too much freedom to third-party developers and the market was swamped with rubbish games.” - Hiroshi Yamauchi, Nintendo's president in 198616


The Nintendo Entertainment System (or NES for short) is an 8-bit home video game console developed and manufactured by Nintendo. It is a remodeled export version of the company's Family Computer[a] (Famicom for short) which launched on July 15, 1983 and hit America during the 1985-1986

The NES was able to bring new life to the video game market, offering high quality 8-bit games.

Also the packages contains true image taken from the game, instead of picture.

For instance compare E.T. and super Mario package pictures versus reality of the game:

Nintendo games was “honest” in the sense they do not try to fool the customer: what you get is very similar to what you see in the picture of the game package.

As we will see, Nintendo will have a firm hand on its games, protecting them via copyright, avoiding third part game producers (like Activision). This will be a winning strategy for more than 20 years, and will be followed by the other company too.

The Nintendo Entertainment System launch

The NES was launched through test markets in New York City and Los Angeles in 1985, before being given a wide release in the rest of North America and parts of Europe in 1986, followed by Australia and other European countries in 1987

The packaging of the launch lineup of NES games bore pictures of close representations of actual onscreen graphics

The release in the Netherlands was in Q4 of 1987, where it was distributed by Bandai BV

In Brazil, the console was released late in 1993 by Playtronic, even after the SNES

The package included the new style NES-101 console, and one redesigned “dogbone” game controller

When Nintendo released the NES in the US, the design styling was deliberately different from that of other game consoles.

NES Hardware

For its CPU, the NES uses the Ricoh 2A03, an 8-bit microprocessor based on a MOS Technology 6502 core, running at 1.79 MHz for the NTSC NES and 1.66 MHz for the PAL version.

The NES contains 2 kB of onboard work RAM. A game cartridge may contain expanded RAM to increase this amount. The sizes of NES games vary from 8 kB (Galaxian) to 1 MB (Metal Slader Glory), but 128 to 384 kB is the most common.

The NES uses a custom-made Picture Processing Unit (PPU) developed by Ricoh. All variations of the PPU feature 2 kB of video RAM, 256 bytes of on-die "object attribute memory" (OAM) to store the positions, colors, and tile indices of up to 64 sprites on the screen, and 28 bytes of on-die palette RAM to allow selection of background and sprite colors.

Sprites was very small: 8 × 8 or 8 × 16 and only 8 sprites was visible per scan line (like the C/64).

If you do the math, for storing 8x8 x 64 sprites you need only 512 bytes. For the 8x16 sprites you need 1Kb.

The console's 2 kB of onboard RAM may be used for tile maps and attributes on the NES board and 8 kB of tile pattern ROM or RAM may be included on a cartridge. The system has an available color palette of 48 colors and 6 grays. Up to 25 simultaneous colors may be used without writing new values mid-frame: a background color, four sets of three tile colors, and four sets of three sprite colors. The NES palette is based on NTSC rather than RGB values. A total of 64 sprites may be displayed onscreen at a given time without reloading sprites mid-screen. The standard display resolution of the NES is 256 horizontal pixels by 240 vertical pixels.

C/64 has a 320 x 200 pixels resolution, so they are quite comparable.

Video output connections vary between console models. […]

The stock NES supports a total of five sound channels, two of which are pulse channels with 4 pulse width settings, one is a triangle wave generator, another is a noise generator (often used for percussion), and the fifth one plays low-quality digital samples.

The NES supports expansion chips contained in certain cartridges to add sound channels and help with data processing. Developers can add these chips to their games, such as the Konami VRC6, Konami VRC7, Sunsoft 5B, Namco 163, and two more by Nintendo itself: the Nintendo FDS wave generator (a modified Ricoh RP2C33 chip with single-cycle wave table-lookup sound support), and the Nintendo Memory Management Controller 5 (MMC5).

Cartige are a double edge sword: it allows to play instantaneously and custom chip expansion but had a higher price.

For instance Sony Playstation will innovate using CD-ROMs, which make the media cost negligible

NES Legacy

The NES was released 35 years ago today. While official NES games haven't been released in over 20 years, a “homebrew” scene exists where developers are still creating NES games (playable on the original hardware or on emulators) in the original 6502 Assembly Language.

From https://github.blog/2018-07-16-how-the-nintendo-entertainment-system-lives-on-in-open-source-game-bytes/

There are some guys who develop NES games today.

NES Mini

In 2016 Nintendo released a “NES Classic Mini”, followed by the SuperNes the next year.


Other References


1984: Commodore 16 and Plus/4: the big failure

1984 is a pivotal year: Tramiel left Commodore at the beginning, for unclear reason, but mostly on disagreement on how to manage the company in the future.

Atari just failed, Apple was in trouble and Commodore was the company selling or licensing the MOS6502 8bit CPU to the rest of the world.

In the 1984 Commodore launched two version of the same base machine called Commodore 16 and Commodore Plus /4.

C/16 was aimed to home whereas Plus/4 should be a “business” machine.

The two units are based on the same hardware: the difference is the amount of RAM of each.

As we will see these computer was a big mistake because failed on a lot of critical aspects:

  1. C/16 has only 16KB of RAM(!) and Plus/4 had 64KB of RAM. A way too little, remember C/64 was released two years ago, so no “cool stuff” here.

  2. VIC-II chip was replaced by TED, which was a step backward because have no sprites, and still have only 40×25 characters.

    On that time, 80 columns was aimed by computers for “office” work, because 40 columns was too little.17

  3. Plus/4 provided 4 program on ROM (word processor, spreadsheet, database, and graphing) but they was:

    1. Not compatible with C/64

    2. Inferior to software provided on C/64. C/64 had a huge software base.

    3. Unable to be upgraded.

Perhaps Tramiel was thinking yet in term of a “calculator” you must turn on and get the software inside, but providing this software on floppy or cartridge would be a way better.

  1. BASIC 3.5 was good but Plus/4 had a rubber based keyboard: another big mistake for a “office” machine.

  2. On the game side, all the games targeted the low-end machine, the C/16, so in effect no one would use the amount of memory of Plus/4
    Gaming was important on that time, because out-of –the box (without additional disks or printers) the Commodore could be used easily as cartige-based console, a sufficient purchase reason.

The Plus/4 was introduced in June 1984 and priced at US$299 (equivalent to $721.07 in 2018). It was discontinued in 1985.

On the same time customers start to buy IBM PC, and Apple computers.


Commodore 128 (1985)

The C128 team:

Software: Fred Bowen, Terry Ryan, Von Ertwine

Hardware: Bil Herd, Dave Haynie, Frank Palaia

Disk Drive: Greg Berlin, Dave Saracusa

Chips: Dave Diorio, Kym Eckert, Eric Chow Yan Yang

Techs: Gale Moyer, Kim Constein, Curt "Arlo" Guthrie, Jeff Brenecke, Lucky Kowlaski,

Chip Layout: Micheal "Monsuer" Angelina, Dave Esposito, Joan Brenecke, "Reverend" Jim Rollhauser, Sandy Roshong

PCB: Terry "Fish" Fisher, Claude Guay, Paul Robino

Management: Adam Chowaniec, Joe Krusuki, Bob Olah, Ed Parks18

The Commodore 128 is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the CES in Las Vegas, it appeared three years after its predecessor, the bestselling Commodore 64.

The C128 is a significantly expanded successor to the C/64, with nearly full compatibility.

/Commodore release cycle was roughly two-year based: for instance Vic20 in 1980, C/64 in 1982, and C/16-Plus/4 on 1984. So C/128 release is a bit odd.
As we will see the C/128 is an unfinished product, which would require additional time to be completed, and it is a very strange beast./

For C/128 we are lucky because we can know the story directly by Bill Herd19 head of the C/128 Project (edited by us):

The Z80 started by me looking at two problems at roughly the same time: 1) The CPM cart was having problems with the C/64, and was sensitive to the version VIC chip and also a brand of 74ls257's, 2) the CPM cart needed about another 1 to 1.5 Amp from the power supply. The C/64 supply just gets hotter and the voltage drops, but the C128 being a switching supply meant that I would have had to specify and pay (times millions) for an extra 1.5 Amp that would probably seldom get used.

Designing the Z80 in costed about $2, and was cheaper than the power supply increase.

So, Z80 was here as a workaround to avoid adding a bigger power supply to the C/128!

Later the Z80 saved our asses when the Magic Voice cartridge (designed by CBM Texas) would crash on a C128 when it tried to jam the reset vectors at boot which would crash since the system was in C128 mode w/ MMU wait[u]ing to be initialized, etc. Overnight we inverted the reset line and called Von the Z80/CPM guy (he wasn't home but his wife was a programmer and read me the assembler code to punch into the eprom burner) and from then on the Z80 booted first. It would carefully look at the cartridge port and if it saw a C/64 cart it would set up the MMU/PLA and then jump to C/64 mode. This is when we also decided to make the C= key be a hard C/64 mode start.


We didn't tell management that we had built in the Z80 until it was too late to stop us. We got a telex from CBM Australia telling us that they would "personally" open the C128's and remove the Z80s if we insisted on shipping with it, which just made us want it more.

Frank Palaia was tasked with all of that crazy jungle logic needed to make the Z80 work using packages already on the motherboard, A PAL would have been safest and easier but it was too costly, took too much power and we didn't make the chip (The Z80 was a rare exception to either using jellybeans or CBM chips.)[…]

So C/128 ended two have two processors, and also two video chips.

The other processor was the MOS 8502, a small evolution 6502. A Memory Management Unit (MMU) was provided to access to the 128Kb via bank switching,

A full feature Basic V7 by Microsoft was provided.

C/128 Motherboard

MOS 8502

MOS 8502 could ran at 2Mhz by the main VIC video chip could not work at that speed and need to be disabled (blank screen). Because little software used the other video chip (VDC) this “FAST” mode was difficult to use: if you get blinded, you for sure cannot show faster screen refresh.

Also, the chip needs banking to access to more memory. Basic V7 tried to use all the 128Kb but was slower then BasicV2 because of bank switching and more commands to address.


CP/M was dead-on-arrival on 1985, superseded by MS-DOS. So CP/M capability would have been interesting in 1982, not in 1985.

Also C/64 compatibility mode was very close to original C/64, and it had the same (slow) speed. So why buy a costly C/128 if all the software park was on the “C/64 Mode”?


As you see in the diagram above, VDC was equipped with 16Kb of video RAM, so it can work on its own. Anyway

  1. VDC missed an interrupt vector synced with the raster.

  2. To program VDC you have to POKE commands into few hardware registers making it very difficult to program.

C/128 Easter eggs


SYS 32800,123,45,6 

Will show you the authors of C/128 also with a “pacific” message in reverse:

C/128 Summary

C/128 was a dual head monitor computer with two CPU and very advanced Basic. Its VDC 80-column mode would position it to the office segment, anyway it shipped without disk drive and with little basic memory for the time it was announced.
So it was a more pricey machine mostly used in C/64 compatibility mode.

In Italy, a magazine called Commodore Computer Club decided to stop publishing C/128 programs while continuing to support C/64 for a while (!) which was a clear signal of the status of the C/128 acceptance by the market.

Price and some bad decision doomed C/128, even if its Basic was powerful and nice. Perhaps if C/128 was delayed a bit, the project would fix some of its bigger mistake like unusable VDC chip.
C/128 will be discontinued in 1989, after 4 years.


Lessons learned form C/64 success (Work in progress)

There is an important lesson I'd like to stress here. I call it software "inertia". In mid '80 there were a huge number of companies which lived developing software for C/64. At some point C/64 become very difficult to kill. Commodore was forced to continue production, and C/128 never took off like expected. C/64 survived to two computers generation (C16+PLUS/4, C/128) which has big design flaw but how was it possible?

C/64 for sure was cheap: in 1986 the "C64C" was a 4-years-old computer produced in a different form factor but with exact the same functionality (more or less) as we saw. It was cheap to produce and cheap to buy.

It was a missed opportunity. If the C64C was a C64 with for instance a bank switching functionality (to address 128Kb of RAM), something like the SuperCPU, but with full retro-compatibility, it could lift the Commodore again.

Or a VIC-III with some retro compatibility. Or two stereo SIDs. A clean migration path from the C/64 to another machine would be great, but was it too complex to achive?


This books uses material from the Wikipedia articles listed below, which are released under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

See https://en.wikipedia.org/wiki/Wikipedia:Reusing_Wikipedia_content for more information.

This book is an experiment. I want to review a huge corpus of product sold between end of seventies and the eighties, without letting my personal sentiment obfuscate the reality of the facts.

After reading a lot of Wikipedia article, you tube videos and so on I decided to write this small book. Then I added my experience, because I have the luck to be a small child in the '80.


Appendix: major reference material

  1. Atari2600

  2. CommodoreInternational

  3. CommodoreVIC-20

  4. Commodore64

  5. Commodore128

  6. Commodore16

  7. Commodore Plus/4

  8. Intellivision

  9. Videogamecrashof1983

  10. NintendoEntertainmentSystem

  11. Simons' BASIC

  12. Commodore65

  13. VICE

  14. MOSTechnology6510

  15. JackTramiel

  16. A mind is Born

  17. Pong

  18. For SID chip see also

  19. For Apple II see https://en.wikipedia.org/wiki/Apple_II

Appendix: reference material in Italian

Il sito microatena offre una vasta selezione di libri in italiano, tra cui:

  1. Guida ufficiale alla programmazione di GEOS http://www.microatena.it/scheda_libro.php?id=66&ord=N#menu_tabs
  2. La serie conoscere il computer direttamente dal computer, basata su audicassette con software didattico della 'Edizioni Beatrice d'Este' http://www.microatena.it/biblioteca.php?id=1&ord=N&p=3#menu_tabs
  3. Giochiamo con il VIC 20, giochi basic in meno di 5k! http://www.microatena.it/scheda_libro.php?id=311&ord=N#menu_tabs

  1. See https://ultimatehistoryvideogames.jimdo.com/computer-space/ for a video of the game

  2. See the Steve Jobs biography and also https://www.businessinsider.com/steve-jobs-on-the-night-shift-at-atari-2014-8?IR=T

  3. Edited from http://oldcomputers.net/c64.html and Chronology of Events in the History of Microcomputers

  4. Scott Adams was a game designer. For more information take a look at https://en.wikipedia.org/wiki/Scott_Adams_(game_designer)

  5. See also https://en.wikipedia.org/wiki/KERNAL

  6. By the way it was far more easy to mix graphics and characters with C/64, because of VIC-II interrupts vectors.

  7. Picture from http://www.aaronbell.com/secret-colours-of-the-commodore-64/

  8. See https://en.wikipedia.org/wiki/Commodore_64 History tab

  9. see http://c64music.blogspot.com/2008/11/new-revolutionary-c64-music-routine.html

  10. Cited from https://www.silicon.co.uk/workspace/pc/commodore-64-history-225855

  11. See https://www.pagetable.com/?p=547

  12. See https://en.wikipedia.org/wiki/Commodore_BASIC#cite_ref-1

  13. See https://en.wikipedia.org/wiki/GEOS_(8-bit_operating_system)

  14. See https://www.lemon64.com/forum/viewtopic.php?t=71262

  15. See also https://www.bugsplat.com/articles/video-games/great-video-game-crash-1983

  16. https://www.bugsplat.com/articles/video-games/great-video-game-crash-1983

  17. See also this video from The 8Bit Guy titled “The Quest for 80 Columns on the Commodore 64” https://youtu.be/BJzOErvJwZs

  18. https://www.reddit.com/r/c128/comments/682da4/c128_ama_from_bil_herd/dgy3sln?utm_source=share&utm_medium=web2x

  19. See https://www.reddit.com/r/c128/comments/682da4/c128_ama_from_bil_herd/dgvcla9/