Have been thinking over the idea of building a retro computer that uses technology from my early computer years. Nowadays I design systems based on modern micro controllers, but the old micro’s hold some nostalgia for me.

So what to build and how should I build it?

My first thought was to use the 6502 processor or the Z80 processor, but so many other bloggers and Youtube channels have built retro computers around these CPU’s. I was thinking about one of my favourite computers from the late 80’s – the Epson HX-20, the first true portable computer – battery powered that lasted up to 40 hours, yes, 40 hours. It’s mad to think that almost 30 years ago we got 40hrs on a computer and todays laptops find it hard to get a day.

This little machine has a built in printer which has been very handy for printing results in the field. It also has a micro-cassette drive, which allows the loading and saving of both programs and data. I used one of these machines between 1985 and 1993, while working in my Dad’s company. We provided loggers to companies and semi-state authorities.

If I decided to build such a device, what could I use it for? Could I make it in such a way that it would be functional and able to complete some meaningful tasks for me? Of course I could use an Arduino or a raspberry Pi, but where would the retro nostalgia be in that.

The Epson HX-20 uses an Hitachi low power CMOS CPU – the HD6301. This chip is a CMOS version of the Motorola 6800 family of IC’s, so maybe this could be the starting point?…

This project will be a work in progress, as I trial different ideas to find a solution that ticks the boxes that I’m interested in. A bit self indulgent I know, but hey, its my project.

My plan is to build something that’s as reliable as an HX-20 but actually better than one?