• Serial Interface

    Matt Callow11/13/2019 at 00:41 0 comments

    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.

  • DataPaks

    Matt Callow11/12/2019 at 11:05 0 comments

    I bought the Psion and a number of blank 32K DataPaks. I have no Comms Link so no means to get any data onto the Psion (other than typing it in).

    So, the first task was to build a DataPak reader/writer.


    Jaap's excellent website https://www.jaapsch.net/psion/ has all the information I needed to build a DataPak reader/writer. Using an adruino pro micro. This uses 8 pins as a data bus, 5  pins for control (RESET, CLOCK, OUTPUT ENABLE, SLOT SELECT and PROGRAM) and one to generate the programming voltage via a boost converter.

    With this, I was able to program the CommsLink 4.2 software into a blank DataPak.