Once, I had the CommLink software installed, the next step was to build the hardware. For this, I again turned to Jaap's site and the schematics drawn by Olivier Gossuin.

(I'm not sure that the schematics are 100% accurate, but they where enough to help me build my own Comms Link)

Since I had the software in a DataPak in slot C, I wasn't sure if it would work with the hardware in the top slot. Only one way to find out - build it and see.

So I built a simple interface using just 2 ICs; a 74HC244 and a 74LS00 (I didnt have a 4011 to hand). I only connected RX and TX (no handshaking signals) and connected them to a USB to serial converter.

It worked! I could communicate between my PC and the Psion at 9600 baud over serial.