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Commodore PET History:

Written by Ian Matthews in February 2003

Last Updated Nov 29 2018

First announced and demonstrated in January of 1977 at the Consumer Electronics Show in Chicago, months before the Apple II or Radio Shack TRS80, the Commodore PET was the worlds first Personal Computer. (See the note at the bottom of this page for a verification of this date).

The PET came fully functional out of the box with:

a keyboard including a separate numeric pad (almost completely unheard of at the time, even as an option)

a 9″ integrated Blue and White monitor

a main board with the powerful new 1 Mhz MOS 6502 processor

many expansion sockets additional RAM or a Processor board

4K of memory

power supply

a cassette tape drive which was a practical storage device for the time

several expansion ports including an RS232 (serial) port

ability to handle and create fantastic graphics (for the time)

upper and lower case text

an operating system that was burned onto a ROM chip and loaded on boot… WOW that was cool

All this was wrapped up in a solid steel, good looking, white chassis. The prototype PET’s chassis (shown in the photo at the top of this page) used rounded edges that was likely designed by Ira Velinsky. Commodore was a notable manufacturer of metal filing cabinets so when it came time for production, they decided to use the now familiar square cases to keep production costs down.

The PET was a revelation as all previous home computers were little more than circuit boards that could only be understood by hard core enthusiasts like the members of the Home Brew Computer clubs.

The first prototype PET demonstrated at the 1977 Consumer Electronics Show had been cobbled together in a hurry and on the cheap. It had a chassis made of wood and a picture tube taken from a $90 black and white TV that MOS bought from a local hardware store.

The visionary engineer behind this project was Chuck Peddle. The worlds first Personal Computer was not ready even a week before the show and in the three days leading up to CES, Chuck worked 20 hours a day getting the PET prototype functional; he completed this now historic task only a few hours before the doors opened.

A year earlier, in the spring of 1976 Chuck Peddle, who worked not for Commodore but for MOS Technologies‘, completed development of the versatile and very inexpensive MOS 6502 processor. He and his largely ex-Motorola colleagues developed the KIM-1 “Computer Trainer” to show off the functionality of this landmark new chip but that was only the start. Chuck developed the PET concept and took it to Radio Shack hoping to have them retail it for him but they were not interested. Soon after, in the summer of 1977, Commodore’s founder Jack Tramiel took a three million dollar loan guarantee from Canada’s Irving Gould to buy Pennsylvania based MOS Technologies, its staff, its patents, it production facilities, along with the PET concept.

At the time Commodore manufactured office equipment like filing cabinets but its biggest business was in calculators so it is no surprise that the original production Commodore PET 2001’s had a sheet metal chassis and calculator style keys dubbed “chiclet keyboards”. These 47 pound beasts were all manufactured in Commodore’s original (and short lived) U.S. facility located in Palo Alto California.

There are several rumours about the source of the name PET. Officially it was an acronym for Personal Electronic Transactor, but P.E.T. are also the initials of founder Jack Tramiel’s wife. Whatever the origin, Jack thought that PET “sounded” good and would have some positive linkage with the Pet Rock fad of the late 1970’s.

The PET made the cover of the October 1977 Popular Science, had a small write up in the February 1978 Playboy and had a very interesting and detailed review from the cover of the February 1978 Electronics Today.

During the first few months Commodore could only produce about 30 machines per day so they could not meet the huge demand. They managed to assemble a meager 500 machines in its first year.

The four kilobyte PET’s (yes that is 4096 bytes which equates to a whopping 4096 characters!) were offered through mail order for $495 and a three to six week wait. Immediately orders starting pouring in and so Jack Tramiel quickly adjusted the price to $595. Then the $795 8K model was actively promoted and the 4K model was downplayed by indicating 8K machines would ship much sooner than 4K machines.

When Commodore expanded to Europe in 1978 Jack doubled the price for the same machine but the only physical change was a 220 watt power supply. The UK \ EU models were sold under the Commodore PET 3008 3016 and 3032 badges. As was almost always the case in those days, Jack’s instincts were right; the re-branded but otherwise identical 3000 series and related future models were highly successful in the European markets at the higher prices.

The COMMODORE BASIC Operating System was written by Bill Gates and Paul Allen from their fledgling Micro-Soft Corporation (later renamed to Microsoft Corporation). Commodore Basic was the only unlimited software license ever granted by Microsoft to any company for all products regardless of the number of copies used. Commodore went on to produce literally millions of machines with various forms of Commodore Basic and did not pay Microsoft a single cent beyond the initial licence purchase in 1976/7.

The PET was a big hit and in these early days of computers. Commodore was receiving as many as 50 requests a day from small, would be computer stores that wanted to sell the PET. Jack was in the luxurious position of being able to pick and choose his dealers. He insisted all stores have:

a good business history

a retail store front

an in store service technician

a parts inventory, and most importantly

pay Commodore a cash deposit in advance for all orders

Within a year Commodore had enough negative feedback about their almost unusable chiclet keyboard that they decided to introduce a standard keyboard model. To make space for the “real” keyboard, they had to remove the integrated cassette tape drive. Just after that, the expensive metal cases were replaced with cheaper plastic cases. By 1980 the PET had a massive 12″ green and white monitor version, dubbed the “Fat 40” which later became standard.

I recall buying my Commodore PET 4016 with 9″ screen, tape drive and a 2031 170K single floppy drive for about CDN$2000 (adjusting for inflation that is about $6000 in 2018!) from my local dealer in Belleville, Ontario in about 1980. I still own that equipment and all devices work like the day they left the factory. (Click on the keyboard picture to the right to see that PET.) At the time Canadian $ were just better than ‘par’ with American $ and that Commodore was a Canadian company with serious operations in Toronto, just a two hours from my house.

Commodore developed many revisions of the PET hardware and firmware, perhaps the most interesting of which is the SuperPET. Using Ontario Canada’s University of Waterloo, Commodore developed the worlds first “co-processor computer”. The Commodore SuperPET was a standard Commodore PET 8032 with 6502 processor, plus an integrated expansion board that carried a Motorola 6809 processor and 64K more memory. In fact there was an $795 ($1750 in 2018 dollars) upgrade kit to convert your 8032 into a SuperPET. The SuperPET manufacturing was contracted to BMB CompuScience of Milton Ontario, Canada.

There were two small toggle switches under the right side of the chassis to change which CPU was in use and in what mode the machine was to operate. The SuperPET ran Waterloo MicroAPL, MicroFORTRAN, MicroBASIC, MicroPASCAL, MicroCOBOL in addition to the standard Commodore Basic v4. It was to be used primarily by scientists and students to work off-line from a company’s or school’s mainframe. A SuperPET could be easily connected to a mainframe and upload whatever was achieved while off-line (i.e. debugged APL code, processed data…). At a time when mainframes cost hundreds of thousands of dollars, the SuperPET was truly an innovative machine with the low low retail price tag of just $2795 (adjusting for inflation that is about $6000 in 2018).

By 1982 PET sales were declining with increased competition and Commodore decided to refresh the line with what Commodore called the CBM-II line: the “B” and “P” Series were conceived. These machines came in many different configurations including ones that did not have integrated monitors. These were the first production computers to sport the snappy Ira Velinsky designed round case which won an international Industrial Design award.

The “P” or Personal Series machines were demonstrated at trade shows and a small number of beta machines were released to Canadian and American dealers to show to prospective clients what they could do. Unfortunately many dealers sold those demo machines. In case you don’t know, beta means pre-release and not finished. As such these beta machines were buggy so they P Series PET’s got a bad name before they were even released. Commodore also thought that the new P Series would cut into their exploding Commodore 64 business so they cancelled the P line all-together. All of the P128 inventory that Commodore was able to retrieve from dealers was plowed into a land fill.

“B” or Business Series machines on the other hand were released in both North America and Europe. A top of the line Commodore B had some very impressive specifications:

two integrated 5.25″ drives with a 1MB of capacity (in 1983!)

two integrated 5.25″ drives with a 1MB of capacity (in 1983!) 128K of RAM expandable to a mind boggling 1MB

powerful 6509 CPU at 1Mhz

potential access to almost every piece of PC business software on the planet (see below)

Zilog Z80 co-processor board that would allow MS DOS 1.25 and CP/M-86 programs to operate

there are only three known 8088 cards in known existence today (2001)

the only programs that were ever developed to run on these cards were “MS-DOS 1.25 for Commodore B Series” and a developer version of CPM-86 (i.e. no real software)

the remarkable Commodore SID sound chip

high resolution graphics

separate keyboard

integrated 80 column, 12″ Display with swivel base (the P Series was colour!)

integrated Commodore Basic Version 7

a smooth, round, sexy case… still today the best looking computer ever mass produced

Even with all this functionality Commodore failed to sell the B Series PET’s in quantity and did not support it with very many “B” specific new programs.

As was always Commodore’s want, they refused to support any of its products with much in the way of advertising. This was the time when other world wide companies like IBM had an advert in every magazine and every night on TV. From the start the B was doomed. Most of the B Series units were sold in Europe, including the West Germany manufactured C710 ‘high boy’ that I own. The most popular B was the B-128 and in the end Commodore managed to sell a measly 15,000 units globally.

Just before Commodore was to plow under the B Series schematics, test machines, and prototype expansion cards, they did what no other computer company had (has?) ever done; hand-over these engineering assets to a third party without charge. The Chicago B128 Users Group (CBUG) became the keeper of all things “B”.

CBUG worldwide members bought hundreds of machines from a company called Protecto Enterprises of New York who were tasked with liquidating the remaining B machines for Commodore.

CBUG developed or distributed so much software, hardware and hype around the B, that it may have actually been a viable product for Commodore produce. However its fate was sealed as Commodore moved on to almost exclusively produce home computers like the VIC20 and C64.

In its last weak attempt to retain some of the Business segment, Commodore then produced a few minor revisions of the original Commodore PET including the 8296, which was supposed to include Paper Clip word processor, Oracle database, CalcResult spreadsheet. Many of these 8296’s had ExecuDesk ROM chip on their main board which would start the software but a user would still have to use ExecuDesk disks to run the applications. ICPUG’s Joe Griffen informs me that the UK models had their software simply provided on diskette. The 8296 that I own (from Britain) definitely did not have any ROM integrated software (although I am very grateful to Ernie Chorny of the Toronto PET Users Group for burning me that chip.)

Thus ended the tale of the amazing Commodore PET.

The three largest factors in Commodores eventual downfall were:

It’s all but complete failure to advertise / promote its products at a time when big players like IBM were spending millions Founder and visionary Jack Tramiel’s departure in 1984 which caused Commodore to lose direction Commodores surrendering of the Business Market to IBM clones when they killed the PET / CBM II lines

My collection of PET’s grows every year. I now have three Chiclet 2001 Pet’s, two standard keyboard 2001 PET’s, my original 4016 PET, one SuperPET, an 8096, an PET 8296, a C710, and a B128 in the factory box. I still enjoy playing with them; they are still amazing machines every after all these years.

Note about the release date of the PET: Because so many other texts and websites wrongly state that the PET was first seem at the West Coast Computer Faire, I re-re-rechecked this timing with Chuck Peddle in April of 2014 and he said “We demo’ed an early version to Radio Shack at the CES and then did some stories in trade mag using the same prototype. So, you are right. General public release was at the West Coast Computer Faire. We had final working versions and sold product in the Dallas Computer Show in late summer. We took first distributor order with check at June CES.” Thank you Chuck!

Commodore PET Documents:

Commodore PET Magazine Articles

Commodore PET Manuals

Commodore PET Brochures

Commodore PET Software Download

Commodore PET Chronology and ROM Versions

Much of the content below was provided courtesy of Joe Giffen of the ICPUG reprinted with permission Feb 21, 2003

1976

Spring 1976 MOS Technologies finishes development of the 6502 processor

September, MOS and the PET concept are bought by Commodore

October, Jack Tramiel approves the development of the PET prototype

1977 January

Chuck Peddle shows the first PET to Radio Shack, hoping to have them retail it.

Commodore PET 2001 announced at the West Coast Computer Faire. A complete unit ready to plug in to a mains supply and go. The machine was programmable in BASIC and set the pattern for many machines to come in that it used a non-standard form of ASCII code (often called PETSCII) in which two complete character sets were available. One set comprised upper and lower case letters while the other, the default, had upper case letters and block graphics symbols. This arrangement has carried right through to the 128. The machine also set the pattern to come with outlets being provided for connection of a second cassette drive, IEEE peripherals and non-intelligent peripherals (via a user port). It was available with 4K of user memory and is most easily recognized by its small calculator style keyboard and built-in cassette drive. The Operating System contained a number of errors, most of which were corrected in later versions of the PET. The Operating System of these early PETs is variously described as “OLD ROM”, “ORIGINAL ROM” or “BASIC1”. These machines power on with the message:

*** COMMODORE BASIC ***

xxxx BYTES FREE

1979 Spring

The 2001-16 and 2001-32, introduced in 1979, were the outcome of the first and most significant revision of the PET. The memory was at the same time expanded to give options of 16K or 32K. A full size GRAPHICS keyboard was fitted leaving no room for a built-in cassette drive. The Operating System was totally revised, becoming what is know as “NEW ROM”, “UPGRADE ROM” or “BASIC2”. This removed most of the bugs of “BASIC1”. These machines power on with the message:

### COMMODORE BASIC ###

xxxxx BYTES FREE

At the same time the peripherals which had been promised for so long finally arrived. These were the 2000 series printers and the 2040 disk drive (DOS 1).

1979 Fall

Commodore releases the upgraded PET 2001 series sporting a larger keyboard, expandability to 32k and an improved (bug fixed) BASIC 1.2 which includes disk support.

The PET was given a new name for sale in Europe, CBM 3000. This was purely a cosmetic change and the machines are as described above for 2001-16 and -32. The dual disk drive 2040 was also rebranded becoming the 3040 for Europe. The new DOS 1.2 had some, but not all, of the bugs removed.

1980 Summer

Commodore PET 4000 Series is born in North America. In the summer of 1980 Commodore introduced a new range of machines, with a further revision of the Operating System, containing built-in Disk Commands. This Operating System is known, from its power-on message as “BASIC4”. Two principal sizes of memory were available, 16K and 32K.

Like their predecessors, these machines had 40 column screens and Graphics keyboards. Originally these machines were fitted with 9″ screens

1981 Summer

Following the introduction of the 8032, 12″ screens were fixed as standard. These later 4000 series machines are commonly referred to as “FAT-40” machines. These machines power on with the message:

*** COMMODORE BASIC 4.0 ***

xxxxx BYTES FREE

The peripherals were again upgraded, the disk drive became the 4040, running DOS 2.1 which allowed true relative files. The printers were replaced with the 4022, a unit based on the successful Epson MX-70. 8000 Series. Shortly after the introduction of the BASIC4 machines, COMMODORE released their first 80 column machine (the 8032). The PET had finally come of age!

This had a 12″ screen and a built-in ‘beeper’. It was fitted with a standard 32K of memory and the BUSINESS keyboard (often criticized by those who grew up with the 40 column machines). These machines power up, in lower case, with the message:

*** commodore basic 4.0 ***

31743 bytes free

With the new machine came a further range of peripherals. The 8050, a high density disk drive was introduced with 500K-bytes of storage on a disk and a 132 column printer (the 8023) also appeared.

Commodore introduces the University of Waterloo engineered SuperPET, a 96k 8000 series PET sporting both a 6502 or 6809 processor. The 6809 mode offers the use of loading in disk based languages and interfacing via a true RS-232 port to larger mini and mainframe computers for programming and language development

It was around this time that a group of workers at Commodore in Japan are alleged to have put together a computer for their children. The machine was designed to plug into a television set and had colour output. There is a rumor that the machine was given BASIC 2, because those were the chips which were lying around the office. I doubt this, because the operating system is not the same BASIC 2 as in the PET, but is a derivative, having different input/output routines and, of course, the colour features. It may be that the only source code available was BASIC 2! Whatever the truth, that machine went on to become the VIC 20 and set the pattern for a range of cheaper home computers leading to the C44. It was their concentration on the expanding home computer market which led, in my opinion, to Commodore’s loss of their lead in the business market.

In 1981 came the first of a number of variants on the 8032; a machine, known as the 8096, having an additional 64K of memory, not directly accessible from BASIC. A further variant, introduced at the same time, was the SuperPET (CBM 9000) (Micro Main-Frame in Europe) with both 6502 and 6809 processors. This supported a number of other languages, including FORTRAN.

1983 – Early

Commodore announced three new ranges of machines (64, 500 and 700). I attended a ‘Commodore Show’ hosted by my dealer and my notes reveal that the 500 and 700 machines were not actually on display. At the time I described the machines as follows:

Commodore 64 – This machine is the cheapest of the new CBM machines. It is an extension of the popular VIC machine and is aimed at the advanced hobbyist.

Commodore 500 – The 500 series is described by CBM as the “Professional/Scientific” computer. The machine features a 40 column colour display, although as with the 64, no screen is provided with the basic machine.

Commodore 700 – This series of machine is described by CBM as the “Business” computer. The machines in this range cater for an 80 column monochrome screen, which can either be supplied with the machine, or in the form of a separate monitor. The machine can run most of the software which is available for our 8032/8096 machines, although some of the more advanced techniques (such as screen addressing) may not work without modification. The 700 series will have BASIC as their standard language but will be able to accept PASCAL, FORTH, LOGO and other “soft-loaded” languages. Additionally, both the 500 and 700 series machines can accept a “second processor” option of either a Z-80 or 8088 microprocessor. These will allow the machine to run under either of the “Industry Standard” systems of CP/M-86 or MS-DOS, allowing a vast range of programs to be used.

Of these machines, the 64 has, of course, been an incredible success; the 500 was still-born and the 700 was re-launched at least twice, before being finally ditched in favour of a revamped version of the 8000 series.

At the time the 700 was announced, the final floppy disk variant, the double sided 8250 was introduced, giving 1 megabyte of storage on standard 5.25 floppies.

In Jan ’83 the 8000 series was given a facelift by adoption of the Porsche designed casing of the 700. A popular rumour at the time suggested that the suffix “-SK” did in fact stand for “Smoove Kase”!

Although the new packaging made a few differences to the connections – edge connectors were replaced with IEEE ‘D’ connectors, the Operating System was the same as on earlier 8000 series machines.

1984 – 1985

Over the next two years Commodore produced a few more variants of the 8000. The 8296 featured 96K of additional RAM. At the time Tom Cranstoun was reported as saying that 32K of this could only be got at by the user opening the machine and changing the links. The final versions of the 8296 were the 8296D with a built in 8250 drive and the 8296GD with a high resolution graphics board and drive. The operating system was still BASIC 4.

February 1986

In America, the 700 (or B) series is currently enjoying far greater support than it ever did when it was available. Commodore gave away most of the rights of the B’s to the Chicago B128 Users Group (CBUG) who have taken ‘the orphan’ to their breast and a truly incredible amount of development work has been carried out by their members.

A 1M-byte expansion is available and the 8088 Second processor which never appeared for sale has been rescued from the depths of Commodore’s research labs and CP/M-86 is now available for the ‘B’.

On the software front, having been given a release by CBM to obtain all material for the ‘B’, their people have managed to set up some good deals with the software houses. Superoffice is available with Superbase V2! Oh, Precision, how we would love that for the 8096. Precision have also produced Superscript 3 for the ‘B’. Version 3 is the menu driven one seen on the 64 and 128. JCL’s 700 workshop was available under licence to CBUG members for about $30, and the Petspeed compiler (my favourite) was available for $99.

CBUG have also obtained a lot of original Commodore documentation (much of it rescued in the nick of time as Corby was closing) including the 8088 schematics & CP/M-86 info (40pp), software dev’t info (302pp) and the original Programmers Reference (798pp).

1986

Commodore abandons the Business market when it dropped the 8296 and ended the ‘PET’ range

How to Identify Your Commodore PET Hardware:

Reprinted with permission of the author, Joe Griffen of the ICPUG Feb 22, 2003

At each introduction of a new machine CBM have provided the users with the chance to upgrade their machines and third parties like Mick Bignall and Supersoft have been in the fore with conversions. Thus the label on the front of the machine may have little bearing on what lies within. Tom Cranstoun has what appears from its labels to be a 2032, large keyboard machine (or is it a 2016!). When switched on, the 9″ screen powers up in lower case with the BASIC 4 legend. Even then, the fact that the machine is an 8096 is hidden.

Switching on a ‘PET’ will reveal what operating system lurks within. For those with BASIC 2 machines, an upgrade to BASIC 4 (while still maintaining the option to switch to BASIC 2) is available from Supersoft. This board, ‘The BASIC 2+4’ normally sold for £65+VAT. The upgrade to BASIC 4 is well worthwhile for the improvements to the operating system (better string handling and disk commands).

Disk drives may be harder to identify. One method which sorts most out is to format a disk in the drive:

OPEN 1,8,15:PRINT#1,”N0:TEST DISK,TD”:CLOSE 1 works with all drives. Follow this with LOAD “$0”,8 then LIST to see the disk directory. The number of blocks free will tell you the drive type:

670 blocks – 2040 or 3040 664 blocks – 4040 2052 blocks – 8050 4133 blocks – 8250

The ‘single density’ drive x040 cannot be upgraded to double density 8050 standard but an upgrade (again from Supersoft) will convert the 2040 or 3040 into a 4040. The normal price was £55+VAT. In addition to providing Relative files, the upgrade removes a number of bugs and gives automatic recognition of the disk without the need for ‘initialization’.

My final advice to all PET owners is to follow my example of 1982; buy Rae West’s book ‘Programming the PET/CBM’ West published by Level Ltd.

Commodore PET Image Gallery:

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Commodore Video: