The S107 and S111 in the computer have the D664 diodes for the 3V clamp. The schematics say they should be D662. The top board is one from my spares which the left most column of diodes is the blue,blue,red D662 diodes like the middle column. The lower board is one from the pdp8 where the left most diodes are blue yellow D664 diodes like the right most column of diodes. All the schematics I found say the left most group of four should be D662 diodes. The EAE S111 boards which were made later have the D662 diodes. The EAE S107 boards have the flip chip hybrid modules so I don't know what diodes were used.
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