• Please review our updated Terms and Rules here
  • Exhibitor application for VCF West 2022 is now open! If you are interested in exhibiting, please fill out the form here.

Stunning Motorola 68000 system made by Computer System Associates USA circa 1984

gottahack

New Member
Joined
May 14, 2022
Messages
4
Hi, David. I have one of these, also in a HP briefcase, but mine doesn't work and no display comes up. I bought it at a flea market many years ago, but just pulled it out of storage and was looking around for info and found this thread.
The power supply looks OK, and if I disconnect the SBC the display lights up and responds to keys, so it's probably OK, too. But it looks like I only have one of the PETEBUG PROMs and two copies of the TUTOR U11 PROM, so I could really use a dump of the PETEBUG pair if you get a chance.
 

Attachments

  • DSCF0506.JPG
    DSCF0506.JPG
    537.7 KB · Views: 19
  • DSCF0505_5.JPG
    DSCF0505_5.JPG
    1.1 MB · Views: 21

Pt68k5

Member
Joined
Feb 18, 2010
Messages
10
Hello Gottahack
I have One of these and am in California
Mine is missing the 8751 chip for the display board, It does have both U10 and U11 petebug, I have been trying to get copies of all three versions.
In looking I think the silicon software was a multi tasking OS, but not sure

Would you want to sell the one you have?
Mine is A-001243
From what david has said the 8751 has the security fuse blown so the chip can't be read

Tony
 
Last edited:

gottahack

New Member
Joined
May 14, 2022
Messages
4
Multi-tasking OS would be neat, but not too useful without documentation.

If you could dump the petebug ROMs for me, I could do some work on reverse-engineering the serial protocol. With that, and some work on how to drive the displays, it might be possible to write an unlocked 8751 program that works the same. I only have 8748's in my parts box, but I see there are still some 8751's on ebay.
 

Bruce Tomlin

Member
Joined
Jan 6, 2010
Messages
41
Location
San Antonio, TX
Holy crap that is such a freaking awesome design. I love everything about it, including the wooden side panels.

And those 7-segment LEDs are wonderfully excessive. From the silkscreen on the plastic, apparently they're intended to display the entire 5-word opcode of the longest possible 68000 instruction.
 

Pt68k5

Member
Joined
Feb 18, 2010
Messages
10
Gottahack
The eprom are 2764
Attached is a zip with the 2 bin files.

The AT89S52 which is a EE part has the same pinout as the 8751 so you can use that for testing
I was think that a vampire tap could be used to capture the serial data from both send and receive lines.
 

Attachments

  • petebug.zip
    2.7 KB · Views: 3

Pt68k5

Member
Joined
Feb 18, 2010
Messages
10
Manual for earlier version of the CSA68000 trainer
 

Attachments

  • csa100.pdf
    1.3 MB · Views: 4
  • csa80.pdf
    1.7 MB · Views: 4
  • csa60.pdf
    1.7 MB · Views: 3
  • csa40.pdf
    1.7 MB · Views: 5
  • csa20.pdf
    1.3 MB · Views: 4
  • csa130.pdf
    1.8 MB · Views: 3

gottahack

New Member
Joined
May 14, 2022
Messages
4
Wow, excellent! The memory map looks very different from what the MECB uses, but having docs for the keyboard operations will help a lot. I'll probably be too tied up with work for the next couple of weeks to do a very deep dive into the machine, but I should have plenty of time after that.
 

Pt68k5

Member
Joined
Feb 18, 2010
Messages
10
Hello, could someone write a serial test program to burn to eprom using the ACIA (6850) address
fd0041 acia 1 status register
fd0043 acia 1 data register
fd0061 acia 2 status register
fd0063 acia 2 data register
 
Top