Repurposing an old Psion MC400 laptop keyboard with Teensyduino & USB

Re-purposing an old Psion MC400 laptop mechanical keyboard from 1989 to work with USB via a Teensy LC (Arduino compatible) microcontroller

Psion MC400 – retro computing via RS232 to Raspberry Pi – handshaking fixed…

Getting the 1990s era Psion MC400 laptop online via an attached Raspberry Pi and some custom shortened Psion serial-USB cables… Tweets, Emails, BBC News & screenshots! All in glorious monochrome and at 19200 baud 🙂