Building an Altairduino, part 1
Introduction
Like many people of my age who are “into computers”, I first got interested in the little silicon marvels in the 1980s, in the era now commonly known as the home computer revolution.
This was the time when a huge number of relatively cheap 8-bit home microcomputers suddenly became available, almost all of them based around either the Zilog Z80 or the CMOS 6502 processors. For a couple of hundred pounds/dollars (still a lot of money back then, but definiely not unachievable for parents on a middle class salary), your child could be the proud owner of a Sinclair ZX Spectrum, a Commodore Vic 20 or 64, a BBC Micro, a Dragon 32, a .... yeah, the list goes on and on. There were a LOT of these things.
And the great thing about them was that they were, to use terminology that came later, plug and play. Simply find a power socket, co-opt the family TV and find a cheap cassette player, and you were in business. Most of us used them to play games, of course, but they all came with some version of the BASIC programming language, and some of us found that we quite enjoyed telling bits of machinery how to do things.
But that was then. For the wannabe computer geeks of a decade earlier things weren't quite so straightforward. The easy-to-use (for hardware designers) CPUs hadn't really appeared yet, and so if you were interested in computers and weren't a huge business, you were very much looking at a home built kit.
Maybe something like this:
This is an Altair 8800, probably the first genuine “home computer”. It was only available in kit form, so you needed to understand how to solder and some basics of electronics, and it cost an awful lot more than the $200 micros of the 80s, but it was still just about affordable.
And look at it: it's full of toggle switches and LEDs. It looks intimidating, and complicated, and everything that a computer should be. None of your easy-to-use fancy keyboards or tape storage or TV output (although all of those were possible with the Altair). Who wouldn't want one?
Now, genuine Altairs are hard to find and very expensive. They don't pop up very often on eBay and when they do you'd need to find thousands of pounds/dollars to buy one. Ahh well.
And then a couple of years ago I found this post on Hackster about using an Arduino to build an Altair clone. The important thing is that although the Arduino does all the emulation of the processor, memory, peripherals, and so on, there are still lots of clicky switches and shiny LEDs.
So yes of course I bookmarked the page, sticking it in amongst dozens of others marked “interesting projects to do one day”.
And now “one day” has arrived. I'll be attempting to build myself a version of the first home blinkenlights computer, or at least something that looks, feels, and behaves like one.
Here is part 2.