For a long while I've wanted to do an electronics project. One of my goals is to make a complete computer from scratch, using an 8-bit microprocessor. But in order to build an 8-bit computer, I need a way to program ROM-chips. This is because when (most) CPUs boot up, they need to fetch the initial program from somewhere, and this somewhere is usually in ROM. My idea for a first project is therefore to make an ATMega-powered programmer for EEPROMs, specifically 286C4s. The entire project will be open source (both software and hardware).

My plan is to develop this project in incremental steps, roughly as follows:

• Prototype A on solderless breadboard, controlled by an Arduino Uno
• Prototype B on solderless breadboard with dedicated ATmega328 microcontroller.
• Standalone Revision A on stripboard

It's likely that I will go on and produce Revision B with a custom printed circuit board.

In my next update, I'll post the first schematic and a picture of the wired-up prototype A.