Telstar, Videotex and Communications

Building a Standalone Softmodem Enabled PABX
Inspired by the article ‘Build your own PABX and Modem Emulator’ by HereBeDragons, this project aims to build on top of that work and create an Asterisk (v18) PABX on a Raspberry Pi with two local extensions and two external connections to the Telstar Viewdata system. The idea is that I can connect a Prestel or Minitel terminal or an 1980s computer with modem, to the Telstar viewdata system.
Gemini 80-Bus

Gemini 80-Bus Resource
This page is designed to bring all of my Gemini software, firmware and documentation into a single resource. I have also included documents that are related to the Gemini system.
Arduino/Raspberry Pi

Removing the Bounce from a Rotary Encoder in C++
This code was developed from an idea by Oleg Mazurov and is presented here as a complete class that can be added as a tab in an Arduino sketch.
Altair, Apple II, BBC Microcomputer and all things CP/M

ZX81 Controls a Nuclear Power Plant
This video is a ‘tongue in cheek’ look at controlling a nuclear power plant with a ZX81 and is inspired by the marketing of the time.