Commodore PET

Commodore PET
Name	Commodore PET
Manufacturer	Commodore International
Family	PET/CBM
Type	Personal computer
Cpu	MOS Technology 6502
Memory	4–96 KB RAM
Os	Commodore BASIC (Microsoft BASIC)
Display	Built‑in monochrome monitor
Sound	None / internal speaker
Media	Cassette, floppy disk
Released	1977

Commodore PET The Commodore PET was an early personal computer introduced in 1977 by a consumer electronics firm. It combined an integrated display, keyboard, and data storage interface in a single enclosure and helped popularize microcomputers among hobbyists, educators, and small businesses. The machine played a role alongside contemporaries in catalyzing the microcomputer revolution and influenced later designs from multiple firms.

History

The PET emerged from efforts at a Montreal firm founded by an entrepreneur and an engineer who had previously worked with chip designers at a semiconductor company and with executives at an electronics firm. Debuting at a major trade show alongside systems from a California company, a Massachusetts startup, and a Seattle outfit, the PET competed with machines developed by engineers from a microprocessor vendor and a software house. Initial orders placed through dealers and distributors reflected interest from colleges, vocational programs, and corporate labs, alongside purchases by retail chains and educational institutions. Over successive years the platform evolved amid shifting partnerships with a chipmaker, a software publisher, and peripheral manufacturers, while facing competition from personal computers introduced by a photocopier company, a Japanese conglomerate, and a British microcomputer firm.

Design and Hardware

The industrial design featured a combined chassis with an integrated cathode‑ray tube sourced from a display manufacturer and a full‑travel typewriter keyboard partly derived from components used in terminal equipment supplied to telecommunications firms and scientific labs. Electronics centered on a microprocessor developed by a Sunnyside semiconductor concern, supported by static RAM chips produced by several memory vendors and programmable peripheral controllers from an I/O specialist. Storage options included a compact tape recorder interface compatible with consumer cassette decks and a single‑ or dual‑drive floppy system produced by a disk drive manufacturer that had worked with data storage firms and automation companies. Expansion relied on an edge connector and bus architecture documented by the original engineering team and adopted by peripheral makers. Cooling and power components were supplied by industrial suppliers that also served measurement instrument and instrumentation firms.

Operating System and Software

Firmware integrated a BASIC interpreter licensed from a prominent software company founded by a Harvard graduate, which had previously ported its language to microprocessors used by small computer firms and hobbyist kits. The system ROM contained a monitor program and character generator developed in collaboration with local software houses and independent programmers who also produced educational titles, business accounting packages, and machine control utilities. Third‑party publishers for distribution channels including mail‑order catalogs, university presses, and software retailers supplied a growing library of word processors, spreadsheets, assemblers, and compilers. Machine language development benefited from publications produced by computer clubs, technical journals, and a network of user groups established in major cities and on college campuses.

Models and Variants

Early models featured a chiclet keyboard and small monochrome display sourced from a consumer electronics supplier; subsequent revisions introduced full‑stroke keyboards and larger CRTs manufactured by an electronics contractor that also supplied displays to arcade game firms and broadcast equipment makers. Disk‑based variants used drives from a peripheral company that later provided storage for business systems and instrument manufacturers. Special editions targeted educational contractors, governmental procurement officers, and retail buyers; some units were rebadged by regional distributors and sold through office equipment suppliers, book chains, and computer stores. Peripheral ecosystems from printer manufacturers, modem vendors, and expansion chassis builders extended capabilities for connection to telephone networks, local area network experiments, and laboratory instrumentation projects.

Reception and Impact =

Contemporary reviews in trade magazines, newspapers, and broadcast segments praised the machine’s all‑in‑one form factor for classrooms and small offices, comparing it with offerings from a major minicomputer firm, a hobbyist kit company, and a corporate microcomputer project from a Massachusetts institute. Critics noted ergonomic issues linked to keyboard suppliers and display vendors, while supporters highlighted affordability and robustness appreciated by vocational trainers, academic departments, and small business owners. The platform influenced design decisions at later consumer electronics companies and computer manufacturers, and contributed to curricula at technical schools and universities. Collectors, museums, and historical societies focused on computing history now preserve units alongside artifacts from pioneering firms, research laboratories, and early software publishers.

Technical Specifications

- CPU: MOS Technology 6502 microprocessor used in systems from multiple manufacturers and studied by computer architecture researchers. - Memory: Configurations ranging from 4 KB to 96 KB of static RAM from memory suppliers used in instrumentation and consumer devices. - ROM: Firmware including a BASIC interpreter licensed from a prominent software company and system monitor routines. - Display: Integrated monochrome CRT manufactured by display contractors serving arcade, broadcast, and instrument markets. - Storage: Cassette interface compatible with consumer recorder manufacturers; optional floppy drives by a third‑party disk vendor used in business systems. - I/O: Parallel and serial interfaces implemented with programmable peripheral controllers supplied by component firms; expansion bus exposed for third‑party peripherals. - Keyboard: Early chiclet keyboards later replaced by full‑stroke assemblies sourced from typewriter and terminal component manufacturers. - Sound: Basic internal speaker similar to those used in terminal equipment and consumer electronics.

Category:1977 introductions