TOPAZ connection without a buffer
Pin Designation Cable colour (from CPU)
1 Chasis Ground
2 Receive data White of brown
3 Transmit data White of orange
4 DTR Blue
5 Signal Grnd Brown
6 Not used
7 RTS Orange
8 CTS White of green
9 Not used
TOPAZ connection with buffer (Strapping required)
Pin Designation Cable colour (from CPU) STRAP
1 Chasis Ground
2 Receive data White of brown
3 Data White of orange
4 DTR Blue 4 & 6
5 Signal Grnd Brown
6 Not used 6 & 4
7 RTS Orange 7 & 8
8 CTS White of green 8 & 7
9 Not used
How do I make an extension cable?:
Use the standard programming cable from the PC,
then connect a X-modem block (25 pin to 25 pin),
connect a 25 to 9 pin adaptor to the x-modem block and
then a standard serial cable (9 pin to 9 pin) to the PABX.
This way you pin configuration will be correct.