I had one of the early Jupiter Aces - the circuit board said something like v1.00 - and it had some added soldered wires on the board, correcting some errors, but it worked well enough. Forth was definitely what attracted me to it - I was frustrated with Basic on my Sinclair XZ81, and Forth seemed like a big step forward. And I think it was.

I was 14 or 15 at the time. The first summer I wrote a whole load of games, mostly in Forth, but sometimes Forth just wasn't fast enough. I got a copy of "Mastering Machine Code on Your ZX81", and learned Z80 machine code. If there was an assembler available, I didn't have it, so this was all hand-assembled. Getting jumps right was a total pain, as was debugging. Generally, it either worked first time, or you started from scratch again. Usually I got there in the end.

I sold those games through a ad in "Your Computer" magazine, and earned back the price of the computer several times. But recording and shipping tapes one at a time got tedious really fast, so I didn't take that any further.

My Ace got modified quite a bit over the next couple of years. An extra 16KB RAM pack was an early addition, taking it to a whopping 19KB. Because Forth was so compact, I never filled that up.

My mother worked for Chubb cash dispensers (ATMs for Americans) at the time, and at some point they scrapped a lot of equipment. She tipped me off, and we went round there one evening and liberated lots of cash dispenser pieces from a skip. Amongst these were several numeric keypads with lovely mechanical keys. I dismantled several keypads to take out all the individual keys and made a proper keyboard to replace the original dead rubber monstrosity.

At school, I was taking O-level Technology, and you had to do a final year project. I'd seen articles in "Your Computer" about competitions where a micro-mouse robot would have to find its way through a maze. That seemed like a cool idea to me, so I decided to make one, despite not really having much idea how. I hadn't done any digital electronics at that time, but my friend Johnny Tombs (who later went on to be a Professor of Electronic Engineering) had decided to make a parallel I/O port for his ZX Spectrum using TTL logic for his Technology project. I'm not sure where Johnny learned about digital electronics, but he knew what he was doing, and designed a nice elegant circuit board and etched it at home. The Ace had the same Z80A CPU as the Spectrum, so I figured his design could be adapted. After a lot of pleading, he gave my his design and spent some time explaining to me how it worked and loaned me his copy of Watford Electronics catalog. A couple of weeks later all the components arrived, and I spent a busy few days soldering up my modified I/O port on veroboard. Compared to Johnny's professional looking version, mine looked like a mess of wires and chips, but it worked!

So then when it wasn't playing games, my Ace rode about on the top of a fairly flaky micromouse, made in the school metalwork shop out of aluminium sheet, some lego motors, and some light sensors to detect maze walls, exploring mazes. It didn't win any prizes but it did get me an A in O-level Technology.

My school was throwing out an old teletype, so I scavenged that. Then I modified the parallel I/O port to output +/- 12V on one pin, and wrote software to bit-bang RS232 at 110 baud. Back before the Internet, just finding the specs for RS232 was not so simple - our local library was a bit limited in that way - but I got there in the end. A lot of guesswork and trial and error. I don't think anyone made a printer for the Ace, so I may have had the only one. Being able to print code listings really helped, even though the teleprinter only printed capital letters.

Somewhere over the years, with my parents moving house multiple times, the Ace disappeared. Many years later, I found one on Ebay, and still have it. But somehow I never fell back in love with it - it just wasn't as good as I remembered my rather non-stock one being at that formative time in my life.

It's great to read a recollection by someone from the UK of a similar age to me. I remember the Jupiter Ace very well and was so interested in Forth that I got the Acornsoft Forth ROM for my BBC Micro. I too made money selling software (and writing magazine articles---mostly about the Research Machines 380Z/480Z).

I think the biggest difference between then and now is the sense of discovery. I spent an enormous amount of time just discovering everything I could about computers and the machines I had access to. Everything from circuit diagrams to compilers. I don't think there's the same level of discovery now because so much else is available. In some ways, a lot of what we could do with a computer was understand the computer itself because other stuff (like games or programs to buy and run) was relatively difficult to get.

Meanwhile, I managed to roast an EEPROM that contained a assembler/disassembler for Z80 by pluging it the wrong way in a weird expansion board for a CPC 6128. It was an expensive Xmas present, I almost passed out when I realized my mistake. I don't remember how old I was when it happened, but definitely not enough to RTFM cautiously.

So I had to stick with Basic until I finally got my first PC. It was the time when one could order floppy disks preloaded with "sharewares" you selected from a catalog. The first and only I order contained A86/D86 [2] and PygmyForth [1]. I picked up a Forth because I saw ads in magazines for Forth systems featuring multitasking and other wonderful things.

I spent a lot of time with those two, and eventually started to program my own Forth interpreter as any sane person should do... I ended up writing a minimal assembler with the help of A86's extensive manual in order to be able to boot my system from a floppy, modify its source with a block editor, and recompile it from scratch, boot sector included. It's sole use ever was to prove myself I could do those "difficult" things.

[1] https://pygmy.utoh.org/pygmyforthmanual.html [2] http://eji.com/a86/

I think I saw a black and white photograph of your micro mouse in British magazine back then. I used to subscribe to “Your Computer” to feed my ZX Spectrum habit.

Awesome story. Which year did you create the micromouse?

Any change you have pictures of it?