Tony Duell sent me the pinouts for the 9915A/B keyboard and control connectors.
The keyboard connector is:
1 : Shield 14 : C0
2 : R0 15 : C1
3 : R1 16 : C2
4 : R2 17 : C3
5 : R3 18 : C4
6 : R4 19 : C5
7 : Ground 20 : C6
8 : Ground 21 : C7
9 : R5 22 : Shift/
10 : R6 23 : Ctrl/
11 : R7 24 : Capslock/
12 : R8 25 : Speaker
13 : R9
The keyboard matrix is the same as the 85, and is connected between the
row (Rn) and column (Cn) lines The shift, control, and capslock keys are
connected between the appropriate pin and ground. The speaker
is an 8 ohm unit, connected between pin 25 and ground.
The Control connector, a DA15, has the following pinout :
1 : LED0 9 : Run/
2 : LED1 10 : Test
3 : LED2 11 : Power OK
4 : LED3 12 : Ground
5 : LED4 13 : StartSw/
6 : LED5 14 : TestSw/
7 : LED6 15 : Shield
8 : LED7
It basically carries the signals used on the front panel PCB. LEDn are
the 8 user-definable LEDs. Run and Test are the signals for the 2 LEDs
with those labels on the panel (note that one seems to be inverted, the
other isn't!). The 2 switch signals correspond to the run and test
switches on the panel -- the external switches go between those signals
and ground.
You can turn on these LEDs with the SLITE(A,B) command
(where A is a mask identifying the LEDs that should be
controlled and B is the action, 1 for ON, -1 for OFF).
The 4 function keys on the left of the front panel are just the user
definable keys on the HP85, and appear in the keyboard matrix as you'd
expect.
The video connector is composite monochrome video at (US) TV scan rates.
Just about any composite mono monitor will work.