falter
Veteran Member
As I write this I'm aware I got two things mixed up an miscategorized the TV Typewriter, which isn't really a 'Pre-Altair Microcomputer'. Meant to put that in other.
Anyway this IS a pre-altair microcomputer, and will be the thread I come back to as I attempt to repair and make operational this amazing Mark-8.
Basically all we know is what we know - it seems to be built from the original kit boards, of which 400 sets were supposedly made. It does not have the original 1K RAM board, but rather three 4K 'Solid State Music' boards which are basically copies of someone else's design, I think, and one of which it has been suggested serves as an EPROM board. For the bus, rather than running wires through holes, the original owner, who I expect was the same Grant Runyan who built my TVT, opted to use 88 pin slots instead. The last of these, which the CPU card sits in, is broken. And it looks like it was actually repaired by the owner at one point - there are traces of glue. I guess he relished the idea of taking this thing apart as much as I do.
It appears to be mostly in good condition, although I think it was likely stored in an attic or garage - it seems to have a lot of that sludgy dust that garages are known for.
There are some 'mystery' sockets installed, each one labelled with blue dymo labelling. I was a bit confused about the numberings at first, which are like, 123, 103, etc. But I think these may be the IC part numbers.. ie 74123, 74103. From the labels, it looks like they were in place to aid in reading from a paper tape reader.
When I was looking at this machine in photos - I wasn't 100% sure these were kit boards. Partly because they are so tarnished - in one photo I have in my archive you can see my unbuilt CPU board next to Grant's board. It's pretty amazing how storage can change PCB appearance.
Very much in awe of this - this feels like a true museum piece. I do hope to make it operate one day.
I'm kind of on the fence about how to handle the photos. Because the forum software requires me to shrink them all to attach, I'm thinking for now I'll link my Google Drive, and then maybe later I can shrink and attach directly so they're saved for posterity.
Anyway this IS a pre-altair microcomputer, and will be the thread I come back to as I attempt to repair and make operational this amazing Mark-8.
Basically all we know is what we know - it seems to be built from the original kit boards, of which 400 sets were supposedly made. It does not have the original 1K RAM board, but rather three 4K 'Solid State Music' boards which are basically copies of someone else's design, I think, and one of which it has been suggested serves as an EPROM board. For the bus, rather than running wires through holes, the original owner, who I expect was the same Grant Runyan who built my TVT, opted to use 88 pin slots instead. The last of these, which the CPU card sits in, is broken. And it looks like it was actually repaired by the owner at one point - there are traces of glue. I guess he relished the idea of taking this thing apart as much as I do.
It appears to be mostly in good condition, although I think it was likely stored in an attic or garage - it seems to have a lot of that sludgy dust that garages are known for.
There are some 'mystery' sockets installed, each one labelled with blue dymo labelling. I was a bit confused about the numberings at first, which are like, 123, 103, etc. But I think these may be the IC part numbers.. ie 74123, 74103. From the labels, it looks like they were in place to aid in reading from a paper tape reader.
When I was looking at this machine in photos - I wasn't 100% sure these were kit boards. Partly because they are so tarnished - in one photo I have in my archive you can see my unbuilt CPU board next to Grant's board. It's pretty amazing how storage can change PCB appearance.
Very much in awe of this - this feels like a true museum piece. I do hope to make it operate one day.
I'm kind of on the fence about how to handle the photos. Because the forum software requires me to shrink them all to attach, I'm thinking for now I'll link my Google Drive, and then maybe later I can shrink and attach directly so they're saved for posterity.
Mark-8 - Grant Runyan - Google Drive
drive.google.com