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• Trump Card BIOS disassembly

  Jacques Pelletier • 06/29/2026 at 06:44 • 0 comments

  I'm currently disassembling the Trump Card's BIOS with Ghidra (Z8001 now supported with my extension! https://github.com/jpelletier/Z8000).

  The disassembly seems to make no sense. It seems some stuff may be missing in the BIOS binary on the TC floppy disks.

  Can somebody who have a working Trump Card make a dump of the BIOS for verification?
  

• Ghidra extension for DOS functions

  Jacques Pelletier • 06/18/2026 at 03:43 • 0 comments

  I found a useful extension for Ghidra for use with DOS executables. It decodes the DOS and BIOS interrupts.

  https://github.com/Gravelbones/GhidraDosToolbox
  This package needed some TLC to make it work with Ghidra 12.1 and later.
  I posted an issue about this where the update is solved, with updated java files attached.
  https://github.com/Gravelbones/GhidraDosToolbox/issues/7
  This will help for disassembling the DOS files for the Trump Card.

• Some clue from disassembly

  Jacques Pelletier • 06/17/2026 at 07:36 • 1 comment

  By disassembling LDZSYS.COM, it seems the Trump Card ports are not mapped as found in the Byte magazine. It uses 3EB, 3ED and 3EF instead of 3E8, 3EC and 3EE. I'll try to remap my ports.

• Z8001 disassembler ready for Ghidra!

  Jacques Pelletier • 06/17/2026 at 05:25 • 0 comments

  I completed the Ghidra extension to support the Z8001. For now, all the z8001 (segmented) instructions can be disassembled. However, many instructions miss the code to implement the instructions (for simulation, I suppose). To develop the extension, I used the opcode tests provided with ASL, which I ported to the GNU AS (z8k-coff-as). GNU AS is not perfect, but ASL is better. The first try is with the binaries included in the Trump Card's disks: I disassembled the program DIAG with Ghidra. A screenshot is shown in the gallery.

• Il nous Ghidra vers un monde meilleur!

  Jacques Pelletier • 06/16/2026 at 09:14 • 0 comments

  I'm about to finish the instruction decoding maybe the next weekend. Many instructions are implemented but I left the more difficult instruction to implement later. I will put the code somewhere public like github, as soon as all instructions can be decoded.
  
  

• Ghidra to the rescue

  Jacques Pelletier • 06/13/2026 at 05:00 • 0 comments

  I started implementing the Z8000 in Ghidra. It frigging worked! I can disassemble an instruction. A much hard milestone achieved!
  Now, much work to do.

• Debug with 3 Alien Probes

  Jacques Pelletier • 06/06/2026 at 15:35 • 0 comments

  With a 3rd Alien Probe (Generic), I probed additional signals routed to the 6116 RAM and the 2 bus buffers enable.

  It looks like the bit bucket is working properly.

  LDZSYS now runs without complaining, but DIAG still doesn't work.

• EPROM address lines bug

  Jacques Pelletier • 05/31/2026 at 12:37 • 0 comments

  The 2 EPROM chips are connected to address LA0 to LA10 instead of LA1 to LA11 so I double the bytes instead of an ugly hardware patch. I use the 2 files BOOTEVEN and BOOTODD, but I doubled every bytes.
  Still with this modification, the DIAG utility doesn't work.

• Flip-flop modifications

  Jacques Pelletier • 05/31/2026 at 11:30 • 0 comments

  I made the modifications of the flip-flop logic and it seems to work. The diag utility goes further but the BBTC still doesn't work yet.

• Debugged the NMI flip flop logic

  Jacques Pelletier • 05/30/2026 at 16:59 • 0 comments

  With the help of my Alien Probes, I found out that the NMI flip flop remains set when activated and a reset signal couldn't reset the chip. 

  So the circuit in the CPLD doesn't work as expected. With TTL logic, the circuit works.

  I made a small modification in the CLPD to check only the NMI flip flop logic, and it works now.

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