Saturday, March 21, 2020

Commodore PET Integrated Cassette Drive

Commodore made many different models of cassette drives, or datasettes as they are often called. The first one was never sold individually, it was built in to the PET 2001, so it never had it's own model number.  It is often called the "white keys" cassette drive or the CT-1020 after the audio recorder it's based on. I simply refer to it as the OEM drive, even though all of them were produced by OEMs.

Commodore OEM internal cassette tape drive
Commodore OEM internal cassette tape driveCommodore OEM internal cassette tape drive (front)Commodore OEM internal cassette tape drive (bottom)

This drive first appeared in the PET 2001 in early December 1977. The labels on the door and above the keys are aluminum and were originally black with white lettering but quickly changed to black text on silver.
Black Label (photo by Giacomo M. Vernoni)Silver Label

Like the retail Sanyo cassette drive used in the prototype and pre-production units, this one also appears to be a modified audio recorder.  There is a speaker grille, a battery compartment and an opening in the front where the audio connectors and carry handle used to be.

It seems that the OEM used an audio recorder they were already producing and custom branded it for Commodore. It's unclear whether the OEM shipped these to Commodore as audio recorders which Commodore then modified, or if the OEM shipped them modified including the Commodore PCB and cable.

The audio cassette recorder version is identical except for the plastic coloring and the commodore PCB. The transport assembly was made by Musashino, the motor is from Canon.
The audio version was sold under many different brands. Below is a Precor model C-1800 R.

Commdore OEM cassette drive and OEM Audio recorderOEM Audio cassette recorder (front)Commdore OEM cassette drive and OEM Audio recorder (bottom)

Commodore OEM cassette drive (internal)OEM Audio tape recorder (internal)
Commodore OEM cassette drive (internal)OEM Audio tape recorder (internal)


This integrated cassette drive was later replaced by the model C2N, which is internally identical and most likely made by the same Taiwanese OEM. Only the plastic housing was changed and an eject feature was added.
C2N external drive
OEM drive, Black C2N and White C2NOEM drive, Black C2N and White C2N

The external version of this tape drive is exceedingly rare.  It was available to order from Commodore but it would seem that not many were sold.  Identical to the internal drive except the corner was not cut off and the cable exited where the power connector would be.
Only three examples have been seen so far.






Saturday, March 7, 2020

The Commodore PET 2001 wooden prototype

Recently John Feagans and Leonard Tramiel opened the wooden PET prototype for the first time in 40 years.

Photos taken Dec 2019 and Jan 2020 at the Computer History Museum, Mountain View, CA.
Photos courtesy of John Feagans, Leonard Tramiel and the Commodore International Historical Society, used with permission.

Photo © Leonard Tramiel, All rights reserved
Photo © Leonard Tramiel, All rights reservedPhoto © Leonard Tramiel, All rights reserved
Photo © Leonard Tramiel, All rights reservedPhoto © Leonard Tramiel, All rights reserved
Photos © Leonard Tramiel, All rights reserved.

This one of a kind prototype hasn’t been seen in many years. These are (AFAIK) the first digital high quality photos of the prototype and the only photos of the interior ever. These photos show details that have never been seen before.
The prototype was built in 1976 and shown for the first time at the Jan 1977 CES in Chicago.  The case and monitor shell are made of wood. Originally painted “harvest yellow” it was re-painted and re-decorated several times in 1977 before finally settling on this color scheme.
The prototype had no IEEE-488 port and reduced ROM space so the kernel is different from the production version. The BASIC was Microsoft basic, not yet modified to become Commodore BASIC.

Photo © John Feagans, All rights reserved.
John Feagans, Leonard Tramiel and the PET Prototype
Photo © John Feagans, All rights reserved.Photo © John Feagans, All rights reserved.
Photo © John Feagans, All rights reserved.Photo © John Feagans, All rights reserved.Photo © John Feagans, All rights reserved.
Photo © John Feagans, All rights reserved.Photo © John Feagans, All rights reserved.
Photo © John Feagans, All rights reserved.
Photo © John Feagans, All rights reserved.Photo © John Feagans, All rights reserved.Photo © John Feagans, All rights reserved.
Photos © John Feagans, All rights reserved.

The prototype was at The Computer Museum in Boston until that museum closed in 2000 and The Computer History Museum in Mountain View, CA acquired much of the Boston museum's collection. It was on display at Stanford university for many years until it was recently returned to the CHM archives. This is catalog number X1279.98 at the Computer History Museum. It is not currently on public display.

PET development gantt chart
Gantt chart in pencil on graph paper from 1967 when Commodore was developing the PET.
Showing project tasks, milestones and assigned engineers. Courtesy of Andy Finkle.



Video from VCF-West 2022. Dr. Leonard Tramiel talks about the search for the prototype.



Below are older photos of the prototype over the years, courtesy of the Commodore International Historical Society and Commodore.ca. These are all the same machine.


Photo from a Commodore press release, date unk.
Probably from the Jan '77 CES Show

At Gametronics, Jan 1977.

At the West Coast Computer Faire, April 1977.
From BYTE Magazine Oct '77
There are subtle differences in the keyboard.

At NCC in Dallas, June 1977.
Chuck Peddle is wearing an exhibitor badge for the '77 NCC show

On the cover of the October 1977 Popular Science
The badge and keyboard are different.
The wood grain was contact paper.

At Commodore’s 25th anniversary event, Dec 1983.
Re-painted white with a new badge and the space-bar moved.

On display in the Gates Information Science building
at Stanford University ca 2000


Unless otherwise noted, all photos and other content are my own, all copyrights reserved.