Category Archives: Reverse engineering

Acorn Speech PHROM TMS6100 Emulator

This project creates a TMS6100 speech PHROM (PHrase Read Only Memory) for use with the TMS5220 Voice Synthesis Processor in an Acorn BBC Microcomputer. Whilst it’s still possible to purchase TMS5220 ICs from sites like Ebay, the TMS6100 was a mask-programmed ROM that Acorn produced specifically for their speech upgrade and is therefore difficult and […]

Reverse Engineering a 1.5 inch Photoframe

Whilst browsing around a local electronics store I noticed they were selling little key-ring photo frames. These little devices had a 1.5 inch 128×128 colour TFT as well as USB, batteries and 16 Mbytes of storage for around 140 pictures. Best of all they were very cheap, so I purchased a few to see if […]

Reverse Engineering the Stylophone

The DubReq Stylophone is an icon of English innovation originally made in the UK during 1968 and famously promoted by Rolf Harris until manufacturing was stopped in 1975. The ‘original’ Stylophone has (since 1975) been remade several times, firstly the ‘new sound’ Stylophone which was based around a 555 timer oscillator and more recently as […]

Valiant Turtle

The Valiant Turtle is a floor roving robot made by Valiant Technologies and was a popular education robot for teaching geometry and programming during the 1980s and 1990s. The robot was first sold in 1983 and was often used with the LOGO programming language. I started writing this article in 2009 when I obtained my […]

UltimateSIMON

UltimateSIMON is a project which takes a broken MB Electronics SIMON game and replaces the original PCB with a completely custom PIC18F2550 based board with improved sound, lights and the ability to be programmed and customised. There’s even a USB header, in case you want to make the project even more crazy. There are a […]

C64 VICE Front-End

The aim of this project was to create a front-end for Commodore 64 emulation using VICE. One of the primary problems with emulators (especially for machines from the ’80s) is that there was no standard keyboard arrangement. In this project I took a broken Commodore 64 computer and replaced the motherboard with a PIC microcontroller […]

Simon18F

Simon18F is a project to replace the custom MB4850 processor of the MB Electronics Simon game with a PIC18F2550; initially to emulate the original Simon games and, later, to enhance the existing games and add new ones. For a video of this project including commentary please see the following: Hardware The Simon18F processor board is […]

Reverse Engineering an MB Electronic Simon Game

The MB Electronics Pocket Simon game has a very simple circuit thanks to the inclusion of a custom MB Electronics processor (the MB4850) which performs nearly all of the functions for the game. The only other significant piece of electronics is a SN75494N chip which interfaces the processor to the light‐bulbs and the built in […]