Found it last night - Processor, RAM, ROM, DUART (2681) and a single 74139 (or was it 138?) for decode. And yep, I've got all the parts. Just got to cobble together an EPROM programmer, probably from an Arduino... I think I've got some UV LEDs to make an eraser too - gonna need an eraser!
You haven't got any JEDEC SRAMs by any chance? I've got a UV_EPROM, and thought I had some 16 kbit RAM chips, but couldn't find any when I looked again :( Don't really want to be bothered wiring up DRAM - too fiddly.
One of my first ever jobs was building an in-circuit EPROM programmer for an Intel 8080-based system. The main problem was not the code, but finding a UV eraser with a drawer big enough to take a whole card of EPROMs, which were soldered, not socketed.
I've just got the Beeb emulator to buld on Android (Beebroid/Eclipse) - Next stop, build(write) a link between the accelerometers and the Beeb's ADCs... Smoke me a kipper
I've got a design somewhere for (I think) a five chip Z-80.
ReplyDeleteProcessor, EPROM, RAM, PIO and some decoding.
Must see if I've got all the bits in my bits box...
(Will this sort of thing be seen in future years as a sort of modern-day "fit a sailing ship in a bottle"?
Quite clever, but ultimately pointless)
I have to admit, I find wiring up busses tedious.
Building a 4-bit TTL computer
ReplyDeleteFound it last night - Processor, RAM, ROM, DUART (2681) and a single 74139 (or was it 138?) for decode.
ReplyDeleteAnd yep, I've got all the parts.
Just got to cobble together an EPROM programmer, probably from an Arduino...
I think I've got some UV LEDs to make an eraser too - gonna need an eraser!
A 74181?
ReplyDeleteThat's cheating!
{Gets his anorak}
ReplyDeleteYou haven't got any JEDEC SRAMs by any chance?
ReplyDeleteI've got a UV_EPROM, and thought I had some 16 kbit RAM chips, but couldn't find any when I looked again :(
Don't really want to be bothered wiring up DRAM - too fiddly.
Not as far as I know. I can't remember the last time I even saw an UV EPROM - let alone erased/programmed one, grandad
ReplyDeleteOK, I suppose I'll just have to knit one out of ferrite cores.
ReplyDeleteNit-one. PERL one
ReplyDeleteBuilding a 6502 in Minecraft
ReplyDeleteOne of my first ever jobs was building an in-circuit EPROM programmer for an Intel 8080-based system.
ReplyDeleteThe main problem was not the code, but finding a UV eraser with a drawer big enough to take a whole card of EPROMs, which were soldered, not socketed.
I've just got the Beeb emulator to buld on Android (Beebroid/Eclipse) - Next stop, build(write) a link between the accelerometers and the Beeb's ADCs... Smoke me a kipper
ReplyDelete