cchaven
Experienced Member
Some of you may have seen a bare bones (chassis, cover, PSU, backplane and front panel only) IMSAI 8080 on everyone's favorite auction site a few months ago. It was missing all but 4 of the switch paddles, as well as all of the S-100 bus cards. I'd always wanted one, but always balked at the prices being asked, but since I tend to like basket cases that I have to do tons of research on in order to repair, I picked this one up. I was able to get a new switch escutcheon from Todd Fischer after a bit of waiting and I repopulated it with S-100 cards I already had plus a few that I picked up for the project. The switch paddles I ordered from a gentleman in Austria as a complete set.
It's now complete! Is it cosmetically perfect? no, as it has some scratches and scuffs. Is it functional yet? no. But it's complete and two of the cards I was able to figure out that it had installed prior, and that it now has again, are the IMSAI SIO-2 serial board and the Tarbell cassette board. Both of these are hard wired to the back panel. The original builder also put the power switch and fuse on the back panel, as there's no sign that either have ever been wired to the normal spots on the PSU board.
To be funcitonal, I first need to go thru and check all of the addresses between the memory boards and then come up with a simple monitor that I could put into a 2708 EPROM that uses the IMSAI SIO-2 board for terminal IO. Currently, I have the following boards installed:
Solid State Music CB1 8080 cpu board, wired to the front panel
Vector 12k PROM/RAM board
Processor Tech 4KRA RAM board
TDL Z16 16k RAM board
SD Systems Versafloppy I floppy controller
IMSAI SIO-2 serial board
PMMI MM-103 modem
Tarbell cassette interface board
Currently, it's sitting out on display, sitting on top of a generic 8" floppy enclosure that holds 2 Siemens FDD 200-8 floppy drives. For the moment, I'm just happy to have it complete..it is a striking looking system. Hopefully at one point though I'll be able to finish getting it up and running.
Jeff
It's now complete! Is it cosmetically perfect? no, as it has some scratches and scuffs. Is it functional yet? no. But it's complete and two of the cards I was able to figure out that it had installed prior, and that it now has again, are the IMSAI SIO-2 serial board and the Tarbell cassette board. Both of these are hard wired to the back panel. The original builder also put the power switch and fuse on the back panel, as there's no sign that either have ever been wired to the normal spots on the PSU board.
To be funcitonal, I first need to go thru and check all of the addresses between the memory boards and then come up with a simple monitor that I could put into a 2708 EPROM that uses the IMSAI SIO-2 board for terminal IO. Currently, I have the following boards installed:
Solid State Music CB1 8080 cpu board, wired to the front panel
Vector 12k PROM/RAM board
Processor Tech 4KRA RAM board
TDL Z16 16k RAM board
SD Systems Versafloppy I floppy controller
IMSAI SIO-2 serial board
PMMI MM-103 modem
Tarbell cassette interface board
Currently, it's sitting out on display, sitting on top of a generic 8" floppy enclosure that holds 2 Siemens FDD 200-8 floppy drives. For the moment, I'm just happy to have it complete..it is a striking looking system. Hopefully at one point though I'll be able to finish getting it up and running.
Jeff
Attachments
Last edited: