The best thing I've builtWehttamman asks: My dad and I once built a go-kart from chipboard, pram wheels and an engine from a lawn mower. It didn't work... so tell us about your favourite things you've made, and whether they were a triumph or complete failure.
(
Scaryduck LIKES EGG, Thu 11 Oct 2012, 12:00)
« Go Back
Wire up 2 Amstrads, win a TaxanAs a kid (I'm 34 now) I had a CPC464, which other Brits will recognise as Alan Sugar's answer to the Commodore 64. Like a lot of 80s kids I learned the BASIC programming language and did a bit of coding... all well and good.
Then I inherited a 2nd CPC464 from a family friend whose kids had grown out of it.. Clearly 2 computers must be networked for maximum efficiency. The CPC464 had no networking hardware apart from a modem that I couldnt afford to buy, I knew nothing about network protocols, but I did know about radio, and electronics
After much cursing, soldering and coding it was done: Home made network adapters connecting the Sound Out port on each CPC464 to the Joystick port of the other via a home-designed and built frequency to voltage converter driving a switching transistor, built out of components bought from Tandy (Radio Shack)
They could act as teletype terminals. The networking protocol wasnt based on data per se. The messages were passed from one PC to the other via Morse Code, and all the coding was to design a program that would time the pulses, when it met a long delay it knew it was at the end of a letter, could compare the saved pulses to a database of letters and write the nearest match to a buffer
With care it was possible to type on-screen using just a remote morse key although better reliability was had with 2 computers as the timing was more predictable
Stage 2 involved going wireless. This was quickly forbidden as the best frequency I could find / achieve for data morse code caused harmonics that overrode Radio Four (turned out multiples of the frequency are a problem)- and morse data networking over home made transmitters wasnt a great success
However
10 years later a major UK PC magazine had a write in contest for 'whacky tech achievements'. I sent my circuit diagrams and a printout of my code.
The 19-inch Taxan monitor I won as a result was huge, and very welcome. At the time (Celeron 500mhz era, for context) that was unusually large. It still works.
(, Thu 11 Oct 2012, 18:07, Reply)
« Go Back