Sources for 8b TTL keyboards (Keytronics)
ard at p850ug1.demon.co.uk
Fri Dec 5 15:49:59 CST 2008
> It's weird, that... I suspect I could rustle up something
> 'traditional' around
> a Z80/6502, ROM, RAM and some decoding - but my brain just doesn't cope well
> with single-chip 'black boxes' such as PIC-based widgets. I really
> don't know why!
My problem with single-chip microcontrolelrs (PICs, etc) is trying to
debug the firmware. If I have external program memory, I can hang a logic
analyser off said memory's address bus and see just what the firmware is
doing. But there's no way to really trace the code running in a PIC.
OK, you can add instructions to set/reset 'spare' port pins at particular
points in the code and see if/when those change. But it's nowhere near as
convenient as being able to trace the code.
I can't afford the real ICE units for the PIC, etc.
And please don't suggest the simulator. I've never found a simulator that
(a) I trust and (b) allows me to correctly simulate all the exernal
hardware I have hanging off the microcontroller.
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