The PETdisk is a simple storage device for the Commodore PET series of computers. PETdisk uses a microSD card for mass storage and uses the PET’s IEEE-488 port. Documentation, schematics, and source code will be provided here. Build your own from scratch, or order a PETdisk fully assembled.

PETdisk Operation Guide
PETdisk Technical Specs and Firmware

Assembled and tested PETdisks are available for $55 USD. These units are tested with my PET 2001 or 8032 before I send them out the door.

The PETdisk has a bootloader which updates its firmware directly from a file on the SD card, so when future updates are available you can easily get the latest features.

Check out these videos of the PETdisk in operation:

If you are interested in ordering a PETdisk unit, please place an order at my store page:
Bitfixer Store

PETdisk users around the world:
PETdisk users around the world

Product Options
1PETdisk assembled$50.00
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Order PETdisk PETdisk assembled @ $50.00

14 Responses to PETdisk

  1. Pingback: Nemesiz V3 Portal » Blog Archiv » PETdisk – SD Kartenleser als Floppyersatz für Commodore PET

  2. Andy says:

    Wow – what a great device! Well done!

  3. xAD says:


    I like a lot your project.

    You have a plan for connect a IEEE-488 Centronics connector?

    Example for my Commodore 8096SK ;-D (

    Best regards.

    • bitfixer says:

      Very cool computer you have there! Where can I get one? :)
      Thanks very much, I think it wouldn’t be too difficult to add an IEEE-488 connector. Without a major redesign, I think the simplest way would be to create a small adapter board with a male IEEE-488 connector on one side and an edge connector on the other. This would plug into the back of the 8096SK, and then the PETdisk would plug into the edge connector. Send me an email at if you’re interested and we can talk about this possibility!

      • Giovi says:

        I did an adapter for that, please take a look at my website ( , look at Commodore page, you will find some info about how to build one for yourself in an easy way. It works fine with PETdisk and my 8032-sk and 8296.

  4. Sir Morris says:

    Awesome stuff! I’m looking forward very much to building one. Thanks for sharing :¬)

  5. Paul says:

    This looks awsome!!! An excellent job well done. I have done internal work with the Commodore drives a long time ago. I am very curious how you implemented the drive emulation in the Atmel. It looks very well polished!!!!

  6. Looking forward to having these at The Centre for Computing History for making our Commodore PET display that bit more interactive :-)
    Excellent Job!

  7. Paul Drescher says:

    This is exactly what makes restoring old computers fun and worthwhile, installing this clever little device is a brilliant use of modern technology, very pleased and well impressed, well done!

  8. mike says:

    thanks, the long-awaited petdisk finally arrived last week.
    i am so happy!
    thank you very much for your work and enthusiasm!
    greetings, mike.

  9. Lanny Fisher says:

    I just bought a Commodore PET 4032 from someone on Kijiji. It came with the PETdisk kit. I must say, very cool!! This will working with my PET so much easier!

  10. SkaBoyTD says:

    I Purchased both the PETdisk and the PETvet from bitfixer, these devices are to cool. Took my old PET 2001 with 8k and turned it into a PET 4032 with 32k Now I can run Telengard! I also love using PETdisk to load my programs into my system.

    Thanks again for the AMAZING products.

  11. Ian Ticehurst says:

    This excellent device helps breathe life back into my PET (CBM 3008) to recall computer programs from 30+ years ago.

    Really easy to use and great flexibility, especially powering via USB.

    Thanks again Mike for continuing to produce PETdisk.

  12. JOHN MENUIS says:

    This is one terrific system that I love. The 4 gig micro sd holds as much data as thousands of the old 360k floppies and gives the advantage of being able to save and retrieve the files to a modern day computer for backup. Thanks for your efforts that have made these old computers useable again without disk drives that are next to impossible to find and even when you do they seldom work. Be wary of old type disk drives like the 4040 on ebay that are listed as untested for they likely are only good for parts or doorstops.

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