Project Logs

Collapse

• Debugging the FPGA

  Jacques Pelletier • 3 hours ago • 0 comments

  So far, the BBTC doesn't work. I removed all the chips on sockets. Only chip remaining on board is the RAM and CPLD.

  At this point, the BBTC's CPLD is programmed.
  

  When I plug the BBTC with the Nano 8088, the Nano 8088 doesn't boot. No video, no message, nothing at all. It boots normally if I remove the BBTC.

  I soldered an unprogrammed CPLD on an empty BBTC and I have the same result. When I put an empty BBTC, the Nano 8088 boots normally.

• Nano 8088 working!

  Jacques Pelletier • 12/07/2025 at 05:40 • 0 comments

  Huge milestone reached!
  I also made a version 2 of the Nano 8088 board because the compact flash connector wasn't available anywhere. Fortunately, once assembled, the board worked! The compact flash doesn't seem to work yet. Once this works, I'll try to push my files on github to the same project.

  Meanwhile, I assembled 2 PCBs from Microcore Labs: the MCLZ8 and the MCL86+. That give alternatives to my alien probes for testing. At least I don't need to debug the 8088 anymore.

  The next test was to plug the BBTC on the passive motherboard along the Nano 8088 v2. Unfortunately, the card blocks the bus and nothing works. When I removed it, the Nano 8088 works normally.

  Next step will be to whip out my Alien Probes. Time to analyse this more deeply!

• Debugging tools under way

  Jacques Pelletier • 11/18/2025 at 08:09 • 0 comments

  My assembled Trump card isn't tested yet, I need a PC to test it. I ordered a Nano 8088 kit with a motherboard but it doesn't work so I need to test both. I make some tools to be able to test the hardware at the lowest level. I call that Alien probes, the name says it all. 

  I made on for the PC XT bus, one for the Z8001, one for the 8088 and a generic one to monitor bits and generate digital signals. These are based on the STM32F405 chip which is similar to the MCU on the black board I used on the Z80 ICE.

  I plan to make Alien Probes for other CPUs used in the retrocomputing community. This will help locate hardware faults.

• Rechecking the bucket logic

  Jacques Pelletier • 10/13/2025 at 14:57 • 0 comments

  I just made a simulation model for the bucket logic.

  In the original Trump Card schematic, I noticed (what seems) a redundancy with the signal /BIOW at IC30 pin 13 and IC33 pin 12. That may explain the 470pF capacitor at the output of IC28 pin 9.

  While the original circuit modif may not be trivial, the CPLD version would be much easier to correct, and no need for capacitor.

• BOM files

  Jacques Pelletier • 09/29/2025 at 05:24 • 0 comments

  I added BOM files to the project. I provided the parameters for the CPLD and the memory chip.

  On eBay:

  Z8001P, Z8581

  On Digikey:

  RAM chip

  Other chips:

  See your favorite suppliers (Digi_Key, eBay, Ali Express, etc.)

• PC104 Version on hold

  Jacques Pelletier • 09/27/2025 at 06:53 • 0 comments

  Due to some personel circumstances, I would like to put this project on hold, unless someone would take it over.

  The schematic has been modified to allow using of different EPROM. or EEPROMs.

  Files available here.

• PC104 version under way

  Jacques Pelletier • 09/23/2025 at 21:59 • 0 comments

  For fun, I'll make a PC104 version of the BBTC. The only DIP chips will be the Z8001, clock generator and the 2 EPROMs. I'll make the EPROM configurable for different chips.

  I'll only provide the files, no PCBs.

• PCB received and assembled

  Jacques Pelletier • 09/03/2025 at 21:15 • 0 comments

  I just received the PCB from JLCPCB and assembled all the component. I need to program the EPROMs and the CPLD.

• Disks and docs for the Trump Card

  Jacques Pelletier • 08/23/2025 at 10:25 • 0 comments

  It's not the Eipstein files but there are zip files for the floppy disk and some documentation.

  See here:

  https://www.dropbox.com/scl/fo/lkmmt6tifnuqre9qxl0td/ANvDDy4Do6DVohqB6sxCs2M?rlkey=9jzjq2vstowaqotr132vabyyw&st=4xxfmd3s&dl=0

  I found this in this forum:

  https://forum.vcfed.org/index.php?threads/z8000-board-for-ibm-pc.1237909/#post-1443617
  

• PCB is ready!

  Jacques Pelletier • 08/22/2025 at 17:05 • 0 comments

  The PCB is completed and Gerbers files are available. See the Github link.

View all 11 project logs