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Commodore 8032 / CompuThink Disk Drive / Woltron ROM-BUS

Commodore CBM 8032 (HP - Early version 1980) - CompuThink Disk Drive Controller - External Dual Disk Drive - Woltron ROM-BUS Adapter

Commodore CBM 8032 (HP – Early version 1980) – CompuThink Disk Drive Controller – External Dual Disk Drive – Woltron ROM-BUS Adapter.

  • COMPU/THINK (CompuThink) Dual Disk Drive Controller with 8k RAM per commodore PET 8032 (It could be a Prototype or a Clone Board with ASSY 001-35 – DD DSK CTL COMP).
  • COMPU/THINK External Dual Disk Drive 800k DD/DS.
  • WOLTRON ROM (CompuThink C-DOS & TOOLKit) + PET/CBM Expansion BUS Adapter + PIA (Peripheral Interface Adapter) Motorola MC6821.

Unfortunately there is no documentation on the net of this Computhink card that seems to be a prototype or a clone, also there is no documentation or photos of the BUS/ROM Adapter by Woltron.

I spent sleepless nights looking for the starting SYS for the disk management software on the eprom, i have disassembled 24k of code (C-DOS Roms / Basic Roms Patched / Edit Roms Patched) in machine language.

I did it and found it the starting sys ($E790 – SYS 59280), although everything seems to work perfectly after the sys command is printed on the screen (*DOS-40*) and by typing the directory command ($d,1) or the format command ($f,1) the floppy starts to run correctly but the head does not move, while the exit command ($h) work correctly,
i need to say that i replaced the FDC1791 and some floppy disk logic and also one floppy disk drive, but nothing changed.

My suspicion falls on the PROM 82S123 there is no dump on the net, reading this PROM of 32 bytes, only the first 8 Bytes are filled, this is right ? we’ll never know.

All EPROM and PROM have been dumped and you can find them in the archive below.

Gallery:

Download: C-DOS 4.0 - Basic/Edit Roms Patched - PROM 82S123 (955)

  1. DukeFawks
    January 30th, 2020 at 02:56 | #1

    I have a similar Computhink board here and read the PROM. The PROM only contains the board’s serial number with 0×3030 in front of it to make it 8 bytes.
    ExpandaPET controllers had the serial number in the ROMs and don’t have the PROM anymore.
    The serial number can be used to make disk readable only by this specific system with this serial number.

    I have the hard/software manuals from the ExpandaPET scanned if you need them.

  2. August 28th, 2020 at 00:13 | #2

    @DukeFawks

    Hi, big sorry for my delay, i have read now your post :| , i’m very interested of your manual (scanned)

    Thanks.

    Dave.

  3. DukeFawks
    September 27th, 2020 at 02:23 | #3

    Here’s all the stuff I have on the Computhink drives:

    https://drive.google.com/file/d/1wKYZWp52_sXB4ERe0zJdse-vSAjSMzn1/view?usp=sharing

  4. September 28th, 2020 at 08:27 | #4
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