Museum restoration of 8800

[philrrtx]

Originally Posted by TomL_12953

All the schematics you need are in the manuals found at

http://vt100.net/mirror/harte/Altair/

Tom Lake

Thanks Tom. I found the schematic for the 4K dynamic memory board there. The 3P+S I/O board turns out to have been made by Processor Technology. So far I haven't found a schematic for it on line. Herb Johnson offers copies of the whole 84-page manual for 20 cents a page, but I hardly need 80 pages of "put this resistor in this hole" for a board that's already built. If anyone knows of an on-line source for this schematic, please let me know.

On a different topic, I'm having no luck at all locating the double spring-loaded switches used in the bottom row. The ST1-3 switch is still made by APEM (successor to American Switch, who made the originals) but none of their distributors currently has any in stock, and I'm not likely to convince any of them to make a special order for two pieces. If anyone knows of a source for that switch, or an alternate manufacturer's part number for same, please let me know.

We have four broken ones on the upper row and two on the lower row. The ST1-1s for data/address entry (upper row) are available from a couple of distributors, but none has the ST1-3.

Phil