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In depth: Commodore 64

1 The father of the Commodore 64

In 1947, a Polish boy named Idek Tramielski - perhaps better known as Jack Tramiel, a name he later assumed - after being saved by the Americans from a concentration camp where he had been imprisoned during the war, decided to emigrate to the States United where he joined the army; here he learned to repair office equipment, like typewriters. In 1953, he bought a repair shop located in the Bronx and, influenced by the military world, he called it Commodore - to be precise: "Commodore Portable Typewriter Company". As the same Tramiel explained in 2007, during a visit to the Computer History Museum of California on the occasion of the twenty-fifth anniversary of the Commodore 64, he wanted to call his company General, but there were many with that name in the States: General Electric, General Motors; so he had thought of Admiral, but even that was already taken. One day in Berlin, Germany, he was in a taxi with his wife when he saw an Opel Commodore in front of them [1]. So it was that the name was chosen, at least this is the official version, although a bit dubious as the Opel Commodore was marketed in 1967, so several years after the establishment of the Tramiel company. The company became the distributor for North America of the Italian Everest calculators (a famous company from Crema, incorporated in 1967 by Olivetti). Subsequently, Tramiel entered into a commercial agreement with a Czechoslovak company that built the typewriters that Commodore later sold in the United States. But since Czechoslovakia was part of the Warsaw Pact member states, Tramiel had to move to Canada to circumvent import restrictions. Thus, in 1955 the company Commodore Business Machines, Inc. (CBM) was officially established in Canada, based in Toronto. In the early 1970s, Commodore began to shift its interest to electronic calculators, leaving the production of mechanical and electromechanical calculators. But the Commodore product most remembered today and the most sold of all times, what comes to mind when we hear the word "Commodore" is the fantastic Commodore 64!

[1] Software Development Times (January 1, 2008), Pag.10

2 Origins

The Commodore electronic calculators were based on Texas Instruments chips. When Texas Instruments also entered the calculators market in 1975, Commodore - which was essentially an assembler - could not compete with the prices charged by those who produced chips on their own. Tramiel then acquired MOS Technology in 1976, a small Pennsylvania company that was in financial trouble, as well as other small companies that worked in the electronics industry. It was one of the MOS engineers, Chuck Peddle, strongly backed by Tramiel directly inside the Commodore as chief engineer, the man who convinced Tramiel that the calculators were now outdated products and that the market was moving in the direction of home computers. Chuck Peddle, inside MOS, had designed the 6502 chip. It was the starting point that led to the development of the Commodore PET and subsequently of the Commodore VIC-20. The C64 was born as an evolution of the predecessor VIC-20, with the intention of offering better graphic and sound capabilities. Initially indeed the name adopted for the new born was Commodore VIC-30, but before the distribution it was changed to Commodore 64, a name that underlined the fact that the computer possessed 64 KB of RAM! The design team was given less than two months to develop a prototype that could be shown at the International Winter Consumer Electronics Show, in January 1982.

3 Inside the Commodore 64

Commodore engineers managed to put together in just 64K of address space all the following:
  • 64K dynamic RAM
  • 1K RAM for colors
  • 8K for the operating system
  • 8K for the BASIC interpreter
  • 4K for character generator
  • Color video controller with high resolution graphic
  • Synthesizer with 3 independent voices
  • 2 I/O parallel ports
  • RS-232 interface

CPU MOS 6510

The MOS 6510 is the direct successor of the MOS 6502. The main technical characteristics are listed below:
  • Internal architecture: 8 bit
  • NMOS logic
  • 8 bit bi-directional I/O port
  • 256 byte internal static RAM
  • Binary and decimal arithmetic
  • Interrupt management capabilities
  • Addressable memory: 64 KB (16 bit address bus)
  • Direct memory access (DMA) capabilities
  • Possibility of working at 1 or 2 MHz
  • Bus compatible with Motorola 68000 bus
  • The operating frequency of the 6510 was about 1 MHz, although there was a small difference between the models for the American market and those for the European market: the processor worked at 0.985 MHz in the PAL version and at 1.023 MHz in NTSC. - Copyright © MMXX. All rights reserved - Designed by Mr.T