It's nice how you've done that multi-screen edit, so that we can see everything at once without you having to wobble around with a handheld camera or anything seasick like that. :)
Thanks :) - although if I'd built my computer 'landscape' rather than 'portrait' of course I wouldn't need to do the multi-screen in the first place ;)
At the moment it's running off a temporary clock board which uses a 32.768kHz crystal run through a series of 16 divide-by-2 gates (taking the clock down to 0.5Hz at the last gate). I tap off the result at the last 8 gates (0.5, 1, 2, 4, 8, 16, 32 and 64Hz) and put that through an 8-to-1 selector which takes a 3-bit input to select one of the 8 lines - that's what the DIP switch is controlling. Previously I was using a 555 timer set up that had variable control but I wanted something that had some discrete fixed clock speeds. When I design the proper clock card I might implement both as well as having a more 'authentic' relay ring counter (which will be a fixed clock speed).
Thanks. Heh, yea, that would be quite a task making this in to a kit ... that said though, there's links to the PCB designs for the newer cards at www.relaycomputer.co.uk/pages/progress/ and I think I'll upload the Gerber files too so you could get any of the PCBs manufactured if you really wanted to make a bit of the computer.
The current (temporary) clock is based on a 32.768KHz crystal divided down and at 32Hz the computer works fine but at 64Hz the relays start locking up. The maximum will be somewhere between those two values (if I had a variable clock) but 32Hz is quick enough.
