G228 REV F SCHEMATIC    REV H PCB    INHIBIT DRIVER (2 7440)

Manual test, using Digital Multimeter to check logic 

NOTES   7440 outputs (active low) are not at connector (drive tranformers)
           but can be 'clipped' at the 330 ohm pullup (to +5V) resistors
           that connect thru the transformers to 7440 outputs
        output 00 is at the top    (pin A is top)
        output 01 is next       
        output 10 is next
        output 11 is at the bottom (pin V is bottom)
        actual outputs are pulses due to transformer coupling. Must scope them.


Note:  "P" for PULLUP OUTPUTS on the open collector outputs;
       Emitters are driven low.
       output pulses low (0.?? v) when active.
       pulse width is ???? when active

TODO:  still need a way to test diodes, output transformers



PINS
 1 I AA1  ENABLE      (NANDed into OUTPUT 00, OUTPUT 01, OUTPUT 10, OUTPUT 11)
 2 I AE2  ENABLE 0/1  (NANDed into OUTPUT 00, OUTPUT 01)
 3 I AN2  ENABLE 2/3  (NANDed into OUTPUT 10, OUTPUT 11)
 4 I AD2  BIT 00      NAND (ENABLE, ENABLE 0/1, BIT 00) is OUTPUT 00
 5 I AD1  BIT 01      NAND (ENABLE, ENABLE 0/1, BIT 01) is OUTPUT 01
 6 I AM2  BIT 10      NAND (ENABLE, ENABLE 2/3, BIT 10) is OUTPUT 10
 7 I AL1  BIT 11      NAND (ENABLE, ENABLE 2/3, BIT 11) is OUTPUT 11
 8 P AL2  OUTPUT 00 COLLECTOR (PULLUP SO CAN SCOPE OUTPUT)
 9 P AK1  OUTPUT 01 COLLECTOR (PULLUP SO CAN SCOPE OUTPUT)
10 P AU2  OUTPUT 10 COLLECTOR (PULLUP SO CAN SCOPE OUTPUT)
11 P AS1  OUTPUT 11 COLLECTOR (PULLUP SO CAN SCOPE OUTPUT)
12 I AF2  OUTPUT 00 EMITTER (ALWAYS GROUNDED)
13 I AE1  OUTPUT 01 EMITTER (ALWAYS GROUNDED)
14 I AP2  OUTPUT 10 EMITTER (ALWAYS GROUNDED)
15 I AM1  OUTPUT 11 EMITTER (ALWAYS GROUNDED)

IIIIIIIPPPPIIII
; turn on OUTPUT 00
110100011110000
; turn on OUTPUT 01
1100100X111
; turn on OUTPUT 10
10100011X11
; turn on OUTPUT 11
1010001111X
; turn all off
00011111111
0011111
0101111
0111111
1001111
1011100 
1100011
1110000
END