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Datapoint 2200 / 5500 Ram display logic board schematics drawn up.

jdreesen

Experienced Member
Joined
Jul 5, 2012
Messages
252
Location
Switzerland
Just as a backup : here is the schematic I have drawn up for the "high-speed" Display Logic Board, as uses in later variants of the Datapoint 2200, the 5500, and probably also the 6600.
These have the programmable characterset as described in the 5500 manual and uses the "diddle-scan" character-per-chararcter display.
Note that the backplane wiring diagram in Bitsavers "2200_drawing_package" is for earlier versions of the machine, my 2200 ( actually a 1131) has a considably expanded backplane.

Interesting to see that there is a serious designerror in this PCB : one of the 120 nF decoupling caps is actually connected to a SRAM address line.......
 

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