UPDATED · 3 OCTOBER 2026

Retro · Commodore PET · 1977

Commodore PET 2001 — Commodore's First Computer

Published 3 June 2026Updated 3 October 2026KAGAMI Ltd.⏱ ~10 min read

In January 1977 a company known for its calculators showed, at a trade show in the US, a computer with a screen, a keyboard and a cassette recorder in a single metal case. The development had to fit into about six months. That is how the story of the PET began — the machine that opened the way to the VIC-20 and the Commodore 64.

Retro MOS 6502 · Commodore BASIC · PETSCII For everyone

UPDATED · 3 OCTOBER 2026 · WHAT WAS UPDATED

Price: ~~“$795 — the 4 KB version”~~ → the 4 KB version cost $495 when first announced and soon afterwards $595; $795 is the price of the 8 KB version. The sources are not unanimous — Wikipedia and oldcomputers.net give $795 as the PET's launch price. [1][4][5][6]
Screen: ~~“monochrome (green/amber)”~~ → a 9-inch monochrome; the original PET 2001 has a white phosphor, the green screen came with the 2001-N model (1979) [6]
The 1977 market: ~~“the first company with a ready-made personal computer… the PET was sold in shops when the Apple II was still a kit”~~ → in 1977 three machines came out, called “the trinity” — the PET, Apple II and TRS-80. The first PETs were delivered in October 1977. [6]
Processor and Chuck Peddle: ~~“the father of the 6502”~~ → Peddle led the design of the 650x family at MOS Technology; the 6502 has a second creator — Bill Mensch [7]
The BASIC example: ~~“POKE 59468,14 — controls the IEEE-488 port”; “32768 — the start of RAM”~~ → 59468 switches the character set (12 — graphics, 14 — lower case); 32768 is the start of video memory [3]
Software: ~~“WordPro — Commodore, 1979”; “VisiCalc ran on the PET”~~ → WordPro is the work of an independent programmer, Steve Punter, not of Commodore; VisiCalc came out first for the Apple II in 1979, and a PET version appeared later [9][10]
Jack Tramiel: ~~“thrown out of Commodore”~~ → resigned in January 1984 after a dispute with the chairman Irving Gould [8]. The timeline of the VIC-20 and C64 has been corrected according to [5].
Removed because they could not be confirmed: the slogan “Computers for the masses, not the classes” as words from 1977; “Commodore sold over 30 million computers”; Logo and InfoPRIME as PET programs; a row “CBM 8000, 1982, European model” (the 8000 series is from 1980); the ROM size “14 KB”.

01 · HOW IT WAS BORNA calculator business and one engineer

Before computers Commodore made calculators and office equipment. In 1976 the company bought the chip maker MOS Technology to secure its supplies [8]. That is how Chuck Peddle came to Commodore — the engineer who at MOS led the design of the 650x family (the 6502 is the best known) and of the KIM-1 board [7]. The Smithsonian describes how he persuaded management that “computers are in fashion” and was allowed to design the PET [1].

Jack Tramiel gave him about six months to have a machine ready for the Consumer Electronics Show in January 1977. The team included John Feagans, Bill Seiler, two Japanese engineers and Tramiel's son Leonard, who helped with the graphic characters of PETSCII [6]. The name “PET” has been expanded as Personal Electronic Transactor, but according to oldcomputers.net it was chosen to ride the fashion for the “pet rock” [5][6].

ℹ

The trinity of 1977

In 1977 three ready-to-use computers came out: the Commodore PET, the Apple II and the Tandy TRS-80. In their history they are called “the trinity” [6]. Which one is the “first” depends on whether you count the announcement, the showing of a prototype or the first deliveries.

02 · THE MACHINEWhat is inside

The PET 2001 is all in one: board, screen, keyboard and cassette recorder in a metal case. The top opens like a car bonnet — the Smithsonian highlights it as a feature of the model [1].

Parameter	PET 2001 (1977)
Processor	MOS 6502, 1 MHz [1][6]
Memory	4 KB (2001-4) or 8 KB (2001-8); the 4 KB version was discontinued in early 1978 [6]
Software in ROM	Commodore BASIC 1.0, built on Microsoft's 6502 BASIC; 8 KB of ROM for BASIC [6]
Screen	Built in, 9 inches, monochrome, 40×25 characters; the original has a white phosphor [1][6]
Keyboard	A small “chiclet” keyboard with a calculator look; often criticised [1][5][6]
Storage	A built-in cassette recorder; a second port for an external one [5][6]
Ports	IEEE-488 for disks and printers, a user port, a memory expansion port [5][6]
Sound	No built-in speaker; a short beep through the port (the CB2 line) [3][6]
Price	$495 → $595 for 4 KB; $795 for 8 KB (sources disagree) [1][4][6]

⚠

There is not just one price

The Smithsonian records $495 for the 4 KB model, Popular Science (1977) — $595 after a quick price rise and $795 for 8 KB, while Wikipedia gives $795 as the launch price. That is why the price is given here as a range. We could not find an original price list from Commodore.

03 · FROM THE SHOW TO THE SHOPA prototype in January, deliveries at the end of the year

A working prototype of the PET 2001 was shown at the winter CES in January 1977 [5][6]. According to Wikipedia the first hundred or so machines were delivered in October 1977, mainly to magazines and software developers, and ordinary buyers could get a PET only from December [6]. oldcomputers.net, on the other hand, notes a showing of the first production machines at the summer CES in June 1977 [5]. The exact dates differ by source.

Demand quickly exceeded production. According to the Smithsonian, Commodore was at first making only about thirty machines a day [1]. An advantage of the PET was its full BASIC with floating-point numbers: the Apple II and TRS-80 had only an integer BASIC in their first six months, and lower case came to them years later [6]. The weak points were the keyboard and the lack of a disk: Commodore lagged about a year behind Apple and Tandy in disk drives [6].

The work on BASIC also has a hidden side. Commodore was the first company to license Microsoft's 6502 BASIC, but it paid only with the PET's deliveries — which were delayed by more than six months, leaving Microsoft short of money [6].

04 · BASIC AND PETSCIIThe language and the symbols of the PET

The PET boots straight into BASIC. Its character set, called PETSCII, also contains graphic symbols — including playing-card suits [6]. With them you draw directly on the text screen, with no separate graphics card.

Here is a small example. The addresses come from the contemporary Leading Edge manual (1979) [3]. Code 147 clears the screen, and 18 and 146 switch reverse characters on and off. Address 32768 is the start of video memory (1000 bytes for 40×25 characters). A POKE to address 59468 selects the character set: 12 — graphics, 14 — lower case [3].

Commodore BASIC · PET 2001 · screen and character set

10 PRINT CHR$(147)                  : REM clear the screen
20 PRINT CHR$(18);"REVERSE ON";CHR$(146);" NORMAL"
30 POKE 59468,14                    : REM lower case (12 = graphics)
40 POKE 32768,1                     : REM the character with screen code 1, top left
50 PRINT PEEK(32768)                : REM will print 1

▸

Different early models

The Leading Edge manual notes that the 2001-8 and the later 2001-16/-32 behave differently in lower-case mode — upper and lower case are swapped there [3]. That is why the example suits the later models best; on an early 2001-8 the result may look different.

05 · SOFTWAREBusiness and school

The PET was sold mostly to business and schools. A few names that can be documented:

VisiCalc — the first spreadsheet for personal computers, released in October 1979 for the Apple II. A PET version came out later, criticised for the small amount of room in the sheet [9].
WordPro — a word-processing program by the independent programmer Steve Punter, described as the first significant word processor for the PET and later for the Commodore 64 [10].
Education — the 4032 model was a great success in schools because it was sturdy and everything was in one case [6].

06 · THE MODELSFrom the 2001 to the SuperPET

Model	Year	Memory	Notable features
PET 2001	1977	4 or 8 KB	The original: chiclet keyboard, built-in cassette recorder, white phosphor; the 4 KB version was discontinued in early 1978 [6]
2001-N / CBM 3000	1979	8, 16 or 32 KB	Full-size keyboard, no built-in cassette recorder, green screen, BASIC 2.0; in Europe as the CBM 3000, because Philips had a competing “PET” brand [6]
4000	1980	8, 16 or 32 KB	BASIC 4.0 with disk commands; 40 columns; a success in schools [6]
8000	1980	32 KB (8096 — 96 KB)	80 columns, a “business” keyboard; the CBM 8032 was announced in May 1980 [5][6]
SuperPET SP9000	1981	—	A CBM 8000 base plus a second processor, a Motorola 6809, and languages such as Fortran, Pascal and COBOL; designed at the University of Waterloo [6]

07 · TIMELINEFrom 1976 to 1984

When	What happens
1976	Commodore buys MOS Technology; Chuck Peddle becomes part of Commodore [5][8]
January 1977	A prototype of the PET 2001 at the winter CES [5][6]
October 1977	The first roughly 100 machines are delivered; in general retail from December (according to Wikipedia) [6]
1979	The 2001-N model with a better keyboard and BASIC 2.0; VisiCalc comes out for the Apple II [6][9]
1980	The 4000 and 8000 series; in Japan the VIC-1001 comes out — the predecessor of the VIC-20 [5][6]
January 1981	Commodore announces the VIC-20 for $299 [5]
1982	The Commodore C64 is shown at the winter CES in January; deliveries begin in September at $595. The PET line is discontinued [5][6]
January 1984	Jack Tramiel resigns after a dispute with Irving Gould; later buys Atari [5][8]

08 · WHAT REMAINEDThe beginning, not the end

The PET was neither the most powerful nor the cheapest computer of its time. But it remained Commodore's first computer platform and showed that an all-in-one machine could be sold to businesses and schools. According to Wikipedia about 219,000 machines were sold — a figure we could not check against a primary source [6].

Commodore's next 8-bit computers kept the 6502 family: the VIC-20 and the Commodore 64 use the 6502 and the closely related 6510 [7]. Everything else in them is different — other video and sound chips, colour graphics and a different peripheral bus.

The people around the PET took different paths. Chuck Peddle left MOS in 1980 and, with Chris Fish, founded Sirius Systems Technology, where he designed the Victor 9000 (Sirius 1) — a 16-bit machine with an Intel 8088, MS-DOS and CP/M-86 from the end of 1981 [7][11]. Jack Tramiel left Commodore in 1984 and bought Atari, after which the Atari ST came out — you can read about it in a separate post.

Today the PET can be run on any computer. The VICE emulator, whose version 3.10 is dated 24 December 2025, supports practically all PET models [12].

09 · SOURCESSources

Smithsonian National Museum of American History, “Commodore PET 2001 Microcomputer” (collection record) — americanhistory.si.edu
Computer History Museum, “Commodore PET 2001-8” (catalogue record, 1977) — computerhistory.org
Leading Edge, “Pocket Reference Guide to Commodore's 2001 PET”, 1979 (a contemporary manual) — masswerk.at
Popular Science, a review of the PET 2001 from 1977, presented by commodore.ca — commodore.ca
oldcomputers.net, “Commodore PET 2001 computer” (secondary) — oldcomputers.net/pet2001.html
Wikipedia, “Commodore PET” (secondary) — en.wikipedia.org/wiki/Commodore_PET
Wikipedia, “Chuck Peddle” (secondary) — en.wikipedia.org/wiki/Chuck_Peddle
Wikipedia, “Commodore International” (secondary) — en.wikipedia.org/wiki/Commodore_International
Wikipedia, “VisiCalc” (secondary) — en.wikipedia.org/wiki/VisiCalc
Wikipedia, “Steve Punter” (secondary) — en.wikipedia.org/wiki/Steve_Punter
Wikipedia, “Victor 9000” (secondary) — en.wikipedia.org/wiki/Victor_9000
VICE — Versatile Commodore Emulator, project website — vice-emu.sourceforge.io

Checked on 3 October 2026. Prices are historical, in dollars of the time. Some of the claims (prices, delivery dates, sales, software details) rest on secondary sources only and are marked in the text.

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