Category Archives: Retro Computers

Articles about retro computers

USB to Quadrature Mouse Adapter

SmallyMouse is a project that creates a USB mouse adaptor for 8-bit Acorn computers including the BBC Micro and Master series machines.  SmallyMouse can emulate the two most popular user-port mice made for the BBC – the AMX mouse and the Marconi RB2 trackball (as used in the BBC Domesday project) and provides a small […]

Acorn Econet Clock V2

Continuing on from my first Acorn Econet Clock project, I received some good feedback and advice from other Acorn enthusiasts and decided to make a slightly more complex version 2 of the clock. The original design was simplistic enough to be built on stripboard however, this revised design is built on a custom PCB with […]

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 […]

Acorn Econet Clock

This project creates an Acorn Econet clock suitable for use with Acorn computers from the 1980s and 90s.  The Acorn Econet network is an EIA-422-B based network that is driven by a differential clock signal.  In the network topology the clock generator is a separate unit that is daisy-chained into the network bus and ensures […]

Nintendo Four Score USB

The Nintendo Four Score is a 4 port joystick adaptor for the original 8-bit NES console which allowed you to plug in 4 joysticks (or ‘joypads’) and play compatible 4 player games. Since my daughter wanted to play some of the NES classics such as Zelda and Mario Bros. I decided to purchase on of […]

Mini xum1541

The mini xum1541 is a USB to Commodore IEC serial adaptor which allows you to connect a Commodore 1541 floppy to a modern PC. The design is based on the ZoomFloppy board and the xum1541 firmware provided by Nate Lawson which he has kindly made available under a GNU General Public License. The mini xum1541 is […]

Commodore SID 6581 Datasheet

This article is a reproduction of the original Commodore 6581 Sound Interface Device (SID) datasheet. I made this by taking a photocopy of an original document and using OCR to capture the content, then the document was hand-edited, formatted for mediawiki and reassembled here with (cleaned-up and straightened) diagrams and tables. The reason for this […]

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 […]

4-Bit Computer

If you’ve ever wondered how electronic devices like computers can count, this article gives a simple introduction to binary and logic and shows how they are tied together with electronics to make both simple and complex computers. Please note: There are a couple of mistakes on the slides in the youtube video which are shown […]

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 […]