J151 SC88PIO

B. Connections

There are three connectors on the board. Pin 1 of each connector is marked, and they are shown here as they appear on the board.


PL1 STEbus connector


PL2. Reset switch connector: 2-pin header

	(1) 1 Switch
	(2) 2 gnd

PL3. I/O connector: 10-way ribbon-cable

channel A data out 1 o o 2 channel A data in
channel A RTS out 3 o o 4 channelA CTS in
gnd 5 o o 6 n/c
channel B CTS in 7 o o 8 channel B RTS out
channel B data in 9 o o 10 channel B data out

PL4. SCB I/O Connector.

  Function Pin Function
+5V 50 49 +5V
+12V 48 47 -12V
Group
4
inputs
CT1 in 46 45 CT0 in
SYNCB in 44 43 RxDB in
RTxCB 42 41 GND
Group

3

outputs
CT1 out 40 39 CT0 out
  38 37  
  36 35  
RTSB 34 33 TxDB
    32 31 GND
Group

2

I/O
Bit 7 30 29 Bit 6
Bit 5 28 27 Bit 4
Bit 3 26 25 Bit 2
Bit 1 24 23 Bit 0
    22 21 GND
Group

1

Inputs
Bit 7 20 19 Bit 6
Bit 5 18 17 Bit 4
Bit 3 16 15 Bit 2
Bit 1 14 13 Bit 0
Latch control 12 11 GND
Group

0

Outputs
Bit 7 10 9 Bit 6
Bit 5 8 7 Bit 4
Bit 3 6 5 Bit 2
Bit 1 4 3 Bit 0
  GND 2 1 GND

Notes:

  1. Groups 1 and 2: Inputs are transparent.
  2. CTO out, CT1 out: Open collector buffered outputs with pullups.
  3. CTO in, CT1 in: Buffered inputs.
  4. Serial signals: Unbuffered.
  5. RxDB: Needs LK1 1A made.
  6. Unmarked pins: Not connected.