Hi Bill, IEEE-696 boards ground S-100 board pins 20, 53 & 70. These pins when grounded will disable the IMSAI front panel functions such as deposit/deposit next and reading the ‘FF’ input port. Some folks have modified their CP-A front panels by cutting these pin traces on the front panel or insulating them with thin tape. Is your front panel still fully operational? I just wanted to mention this as IEEE-696 boards can’t coexist with an operational CP-A front panel without these mods. Regards, Jeff On Mon, May 15, 2023 at 9:05 PM Bill Degnan via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Hey all, I posted the basics of upgrading an IMSAI 8080 with front panel to use 64K IEEE 696 RAM and thought some here might be interested. The newer s-100 bus standard (IEEE 696) conflicts with the older S-100 systems (PHANTOM disrupts the Altair/IMSAI front panel). BUT if you can resolve the bus conflicts, newer RAM boards are less electrically noisy and they help make for a more stable system. More RAM the better. Worth the effort.
So, if you're interested, here is how I got the Morrow MM65K 64K RAM board to work on my IMSAI: https://www.vintagecomputer.net/browse_thread.cfm?id=811
I provide links to sources including Jon Chapman's GWMON-80 ROM and Herb Johnson's info about S-100 bus particulars.
For the upcoming workshop this Saturday at Kennett Classic for my project I plan to hack into an ancient hard drive that is password protected by using an Z80 in-circuit emulator to extract the password (hopefully). I also have a NABU computer that I want to map out with the emulator. Maybe I can get a little help with my PDP-8 (straight 8).
Hope to see you there. Let me know what you're bringing/wanted. Here is a link to the event page: https://www.kennettclassic.com/spring-hack-a-thon-may-20th-2023/
If you want to get on the event mailing list: https://www.kennettclassic.com/contact.cfm
I have not posted much about the swap end, but there will be items for sale, I have a few vendors who plan to attend. I will have a table or two of choice items, spares/donations to Kennett Classic
Bill