The Commodore PET is a line of personal computers produced starting in 1977 by Commodore International. A single all-in-one case combines a MOS Technology 6502 microprocessor, Commodore BASIC in read-only memory, keyboard, monochrome monitor, and, in early models, a cassette deck.
Development of the system began in 1976, and it was demonstrated and sold as the first personal computer for the masses at the January 1977 Consumer Electronics Show. The name "PET" was suggested by Andre Souson after he saw the Pet Rock in Los Gatos, and stated they were going to make the "pet computer". It was backronymed to Personal Electronic Transactor. Byte referred to the PET, Apple II and Tandy TRS-80 collectively as the "1977 trinity".
Following the initial PET 2001, the design was updated through a series of models with more memory, better keyboard, larger screen, and other modifications. The systems were a top seller in the Canadian and United States education markets, as well as for business use in Europe.
The PET line was discontinued in 1982 after approximately 219,000 machines were sold.
History
Origins
In the 1970s, Commodore was one of many electronics companies selling calculators designed around Texas Instruments (TI) chips. TI faced increasing competition from Japanese vertically integrated companies who were using new CMOS-based processors and had a lower total cost of production. These companies began to undercut TI business, so TI responded by entering the calculator market directly in 1975. As a result, TI was selling complete calculators at lower price points than they sold just the chipset to their former customers, and the industry that had built up around it was frozen out of the market.
Commodore initially responded by beginning their own attempt to form a vertically integrated calculator line as well, purchasing a vendor in California that was working on a competitive CMOS calculator chip and an LED production line.
They also went looking for a company with an existing calculator chip line, something to tide them over in the immediate term, and this led them to MOS Technology. MOS had been building calculator chips for some time, but more recently had begun to branch out into new markets with its 6502 microprocessor design, which they were trying to bring to market. Along with the 6502 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 and that Commodore should explore the burgeoning microcomputer market instead. At first, they considered purchasing an existing design, and in September 1976 Peddle got a demonstration of Steve Jobs and Steve Wozniak's Apple II prototype. Steve Jobs was offering to sell it to Commodore, but Commodore considered Jobs's offer too expensive.
Release
The Commodore PET was officially announced in 1976 and Jack Tramiel gave Chuck Peddle six months to have the computer ready for the January 1977 Consumer Electronics Show, with his team including John Feagans, Bill Seiler, two Japanese engineers named Fujiyama and Aoji, and Jack's son Leonard Tramiel, who helped design the PETSCII graphic characters and acted as quality control.
The result was Commodore's first mass-market personal computer, the PET, the first model of which was the PET 2001. Its 6502 processor controlled the screen, keyboard, cassette tape recorders and any peripherals connected to one of the computer's several expansion ports.
The PET 2001 included either (2001-4) or (2001-8) of 8-bit RAM, and was essentially a single-board computer with discrete logic driving a small built-in monochrome monitor with character graphics, enclosed in a sheet metal case that reflected Commodore's background as a manufacturer of office equipment.
The machine also included a built-in Datasette for data storage located on the front of the case, which left little room for the keyboard. The data transfer rate to cassette tape was 1500 baud, but the data was recorded to tape twice for safety, giving an effective rate of 750 baud.
The computer's main board carried four expansion ports: extra memory, a second cassette tape recorder interface, a parallel ("user") port which could be used for sound output or connection to "user" projects or non-Commodore devices and a parallel IEEE-488 port which allowed for daisy-chaining peripherals such as disk drives and printers.