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ldkraemer
June 13th, 2015, 03:48 AM
Does anyone have an interest in a Digital copy of the Xerox 820 Service Manual? I've stumbled across a copy in my file cabinet.


Thanks.


Larry

Chuckster_in_Jax
June 13th, 2015, 10:11 AM
Actually, Bitsavers.org has one listed.

mloewen
June 13th, 2015, 08:53 PM
Does anyone have an interest in a Digital copy of the Xerox 820 Service Manual? I've stumbled across a copy in my file cabinet.


Is this an 820, or an 820-II? I'm looking for the keyboard schematic for an 820-II, which isn't in the 820-II manual on Bitsavers.

ldkraemer
June 14th, 2015, 04:17 AM
mlowen,
The paper copy says for 820, but it also has schematics for 820-II CPU included. It has the KEY Numbering chart, the Key Code Chart (2 ^ 8 = 256 Key Codes) for the Parallel
transmission of ASCII Codes with STROBE. It also shows the Parallel interface and the Power Plug to the Keyboard. But, no actual schematic of the actual Keyboard, or
copper circuit traces, if that is what you are looking for.

Larry

mloewen
June 14th, 2015, 07:40 AM
mlowen,
The paper copy says for 820, but it also has schematics for 820-II CPU included. It has the KEY Numbering chart, the Key Code Chart (2 ^ 8 = 256 Key Codes) for the Parallel
transmission of ASCII Codes with STROBE. It also shows the Parallel interface and the Power Plug to the Keyboard. But, no actual schematic of the actual Keyboard, or
copper circuit traces, if that is what you are looking for.


Thanks Larry. All that information is in the Bitsavers manual, and I am indeed looking for the schematic for the keyboard, itself. There appear to have been several keyboards provided with the 820-II, some of which are described as "magnetic valve" or "magnetic gate" types. Mine is not one of those, and appears to be some form of capacitve sensing circuit. I've managed to repair my keyboard, but would still like to find the schematic.