... a few comments have been turning over and over in the murky depths of my mind. Combined with the potent fuel that is Badger Tanglefoot, they've finally fired a spark across a synapse or two, and I had an idea. I'm not sure it's a very good idea (you know in cartoons a lightbulb appears above a character's head? Well there's this lightbulb but it's all dim and flickery and going bzzzt bzzt bzzzzt) but I'll share it anyway.
Bendable drum machines aren't exactly uncommon. The bits inside them are, though. If you fry the big custom chips inside, you're hosed. No replacements, no spec, no manuals, that's it. Mask-programmed chips too usually, so you can't even burn a replacement onto an EPROM without the factory firmware. Sample ROMs and firmware ROMs are easy, but not programmable logic (like the timer/counter/accumulator chip in my late lamented TR626).
So - we have some nice old drum machines getting hacked about and quite often broken. Not really a sustainable state of affairs, is it? I'd like to offer a solution to this.
How about a simple MIDI sound module, available as a bare board that you can case up yourself, which takes an EPROM full of 8-bit samples and plays them back. That's it. You can set the tuning, but that's your lot. If you feel inclined you could build an output demultiplexer and get individual outs, possibly with their own volume controls. Think in terms of a 27C512 EPROM with eight samples, each 8k long, playing back at maybe 22kHz (maybe less, depending on CPU horsepower).
I reckon I could make a PCB which you'd assemble yourself, with the complete kit price coming in about 40-50 quid. Obviously I'd be publishing the PCB layout and firmware source under a suitable licence (GPL firmware, something similar for HW design), but if I sold even ten kits at 50 quid then I'd have more-or-less made back the time I expect it would take to design and prototype.
Thoughts, objections, or anything else, please.
Oh, and you'll need to at least know more than how to change the fuse in a 13A plug. Sorry, that's just how it is.