VCI Cable

For direct Serial port to Mark 4 cable connection (i.e. not using modems) please make up a specific cable with the pin-out as follows:

	Repeater 25 pin	Computer 25 pin	Computer 9 pin
FG	1	1	n/c
TX	2	3	2
RX	3	2	3
RTS	4	8	1
SG	7	7	5

Please Note:

• a) do NOT use any adapters etc. This cable must plug directly into the Female socket on the Mk 4 and the Male socket (25 or 9) on the computer
• b) This cable is UNIDIRECTIONAL
• c) It can be made with a 9 and 25 pin plug pigtailed together on the computer end so that it is transportable to any computer
• d) No other pins should be used
• e) Shielded cable can be used, solder to plug cases only, but is not at all necessary.

For your info:

• a) it is possible to accidentally come up with a combination of cables, null modems, adapters, gender benders etc that meets the above requirements. But because this is not reproducible at all easily, we are not even going to attempt to describe such a set up....
• b) This only applies to non-telephone/modem connections
• c) the RTS to Carrier Detect is necessary for our software (pin 4 goes low after a QUI/BYE and we need the opposite high from the prompt). CTS (pin 5) is not required.