Here's my update version and some notes at the end:
A B C
01 A2K_00 A2K_01 A2K_02
02 A2K_03 A2K_04 A2K_05
03 A2K_06 A2K_07 A2K_08
04 A2K_09 A2K_10 BCD_00
05 BCD_01 BCD_02 BCD_03
06 BCD_10 BCD_11 BCD_12
07 BCD_13 BCD_20 BCD_21
08 BCD_22 BCD_23 BCD_30
09 BCD_31 BCD_32 BCD_33
10 A2K_11 xxxxxxx xxxxxxx
11 -15V -15V -15V
12 -15VX -15Vx -15Vx (IC20 - OP07)
13 +15V +15V +15V
14 +15VX +15Vx +15Vx (IC20 - OP07)
15 GND GND GND
16 GND GND GND
17 +5V +5V +5V
18 +5V +5V +5V
19 xxxxxxx xxxxxxx xxxxxxx
20 xxxxxxx xxxxxxx xxxxxxx
21 xxxxxxx xxxxxxx xxxxxxx
22 xxxxxxx xxxxxxx xxxxxxx
23 xxxxxxx xxxxxxx xxxxxxx
24 xxxxxxx xxxxxxx xxxxxxx
25 xxxxxxx xxxxxxx xxxxxxx
26 xxxxxxx xxxxxxx xxxxxxx
27 xxxxxxx xxxxxxx xxxxxxx
28 xxxxxxx xxxxxxx xxxxxxx
29 xxxxxxx xxxxxxx xxxxxxx
20 xxxxxxx xxxxxxx xxxxxxx
31 xxxxxxx xxxxxxx xxxxxxx
32 GND_12V GND_12V GND_12V
NOTES:
- The LE signal of the BCD inputs is not on the connector, is a NOR output (IC4 74HC32), it could be that the data outputs of the 2K EPROM are used to do some switching.
- Interesting to see how the relays are controled, therr is this beefy ULN Darlington array.
- Is U20 the final amplifier for the output or is special put for the DAC reference voltage ?
Cheers,
DC1MC