I attempted to reverse-engineer the bus, but i stopped short of the processor bus.

Video Deflection
Solder Side | Component Side |
Gnd | Gnd |
5V | 5V |
12V | 12V |
-12V | -12V |
-5V | -5V |
+26V | +26V |
Write | Write |
Write | Write |
Horizontal | Horizontal |
Horizontal | Horizontal |
Vertical | Vertical |
Vertical | Vertical |
Heater | Heater |
Heater | Heater |
Cathode | Cathode |
Grid 1 | Grid 1 |
Grid 7 | Grid 7 |
Grid 2 | Grid 2 |
+26V xxx | +26V xxx |
+400V | +400V |
+68V | +68V |
5V | 5V |
Gnd | Gnd |
Power Supply (pretty sure there are a few errors here!)
Solder Side | Component Side |
Gnd | Gnd |
+5V | +5V |
+12V | +12V |
-12V | -12V |
-5V | -5V |
26V | 26V |
9VAC | 9VAC |
9VAC | 9VAC |
9VAC_Ret | 9VAC_Ret |
9VAC_Ret | 9VAC_Ret |
16VAC | 16VAC |
16VAC_Ret | 16VAC_Ret |
Gnd | Gnd |
Gnd | Gnd |
Gnd | Gnd |
26VAC | 26VAC |
26VAC_Ret | 26VAC_Ret |
13VAC | 13VAC |
13VAC_Ret | 13VAC_Ret |
+5V | +5V |
+5V | +5V |
Gnd | Gnd |
Microbus
Solder Side | Component Side |
Gnd | Gnd |
+5V | +5V |
+12V | +12V |
-12V | -12V |
-5V | -5V |
26V | 26V |
+26V | +26V |
-5V | -5V |
-12V | -12V |
+12V | +12V |
+5V | +5V |
Gnd | Gnd |