Recent Articles
Retro Challenge 2017/4 - Keyboard Investigations
After a visual check of the keyboards (see this post), I had a couple of questions, which were do the keyboards work? and how do the keyboards work?
On the basis that neither of the Alphameric had their EPROM windows covered, and that one of the Cherry keyboards had already been modified, I chose the other Cherry one as the most likely to work. After opening it up (again), I checked the 20 pin header. It was quite easy to find out what the 5v and Ground pins were (traceable to the power pins on the logic chips and corresponds to red and black wires on pin 1 & 2!), but the others were going to need something more to diagnose
Time to break out the oscilloscope! It didn't take long to discover that the pins 3-9 changed upon pressing a key. Curiously, they didn't didn't change when releasing the key though. Also, depending on which key was pressed, they might not change at all. Pin 9 was most likely to change and pin 3 was least likely to change.
Retro Challenge 2017/4 - The Key(board) to Happiness
Next up on the things to investigate is the 4 keyboards
Judging by the connectors, it was obvious that these aren't modern (PS2, USB or even 5 pin DIN) keyboards. Likely either a raw matrix or maybe parallel ASCII. Lets open them up and have a poke around!
Retro Challenge 2017/4 - ICE ICE Maybe
I decided the easiest thing to tackle first would be the three ICE (In-Circuit Emulators) as they're quite bulky things to get out of the way early. There are two non-identical versions of the same model Adtek ICE Engine BX and a Zax ICD278 - all with manuals!
Retro Challenge 2017/4 - Getting The Excuses In Early
So, once again Retro Challenge is upon us, and, yes, the timing is offset , but an April challenge should mean that more people are able to participate.
To try and stay ahead of the curve this time, I thought I'd get in early and give my excuses for why I failed to complete the challenge this time around. I know most people leave this part until the very end, so hopefully I can impress the judges with my efficiency!
The very first weekend in April was the UK Maker Faire in Newcastle (which was awesome, thank you for asking), so that took 3 days out of April for me. Then at Easter the Edinburgh Mini Maker Faire will also be robbing me of 3 days. And, finally, Vintage Computer Festival Europe is on from 29th April to 1st May. So, with travel and prep for these events, I feel like I'll be left with about 4.5 days in which to complete the challenge. Lets see how that works out...
Retro Challenge January 2016 - Preamble
So, you may well remember that I entered Retro Challenge 18 months ago, and what a fun crazy busy time that was! Well, the January Retro Challenge competition is about to kick off in just over 2 weeks.
If you're not familiar with Retro Challenge, shame on you! But you can de-shame yourself by heading over to http://www.retrochallenge.org/ and seeing what it's all about. Essentially, it's a month long bi-annual competition where the entrants set themselves a goal based around old school computing and blog, tweet and share their experiences. The goals are pretty loose, as long as they are based on something from last centuary (modern emulators of old kit is fine).
The challenge I set myself was to take a breadboard based Z80 computer and bring it to life in modular PCB form in such a way that I could spell out my name on. Have a look back through my blog to see how I did. Spoiler ---->
Ace adventures on Jupiter
So, before I dive in to this, a quick history lesson for those of you that aren't fully up to speed on your rare 80's vintage 8 bit computers. In the beginning, there was Clive Sinclair, and he invented the Sinclair ZX80. From the ZX80, the ZX81 and indeed home computing was born. From the ZX81 came the ZX Spectrum. Ok, so Clive didn't invent these single handed. He had a team working for him, which included Steven Vickers and Richard Altwasser. Somewhere between the initial design of the ZX Spectrum and its launch, Vickers and Altwasser thought there was a better way to do things, and left to set up their own computer company.
Jupiter Cantab was formed in 1982, and Vickers and Altwasser developed the Jupiter ACE. This little computer was a weird mix of ZX80 (vacuum formed white case), ZX81 (black & white low res graphics, 3k memory) and ZX Spectrum (rubber keyboard, small speaker). The one fundamental difference, however, was that it used FORTH instead of BASIC as it's operating system. FORTH was much more efficient than BASIC, and would revolutionise the home computer market...
Although history tells us it didn't. Cantab went bust after 18 months and was bought by Boldfield Computing, who went on to sell off the remaining hardware in 1985. Approximately 8000 units were manufactured.
When I was offered an original unpopulated Jupiter ACE by John Fletcher, it was too good to turn down...
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