newbie building a scratch-built computer
cclist at sydex.com
Fri Aug 3 18:43:06 CDT 2007
On 2 Aug 2007 at 23:52, Pete Edwards wrote:
> I've just got to a major milestone on a 6502 based prototype (ie it
> actually runs my code :) and I've got to say I felt I'd actually
> achieved something special after debugging with nowt but a meter and
> led+resistor probe(s).
Good job! It's surprising how far one can get without a scope or a
logic analyzer. I'd recommend, though, that you put together a
"pulse sniffer"--little more than a one-shot driving an LED to
"stretch" pulses so they're easily visible. Often, a simple LED
level indicator on a pulsing line won't show a thing, leaving you to
scratch your head and wonder what you missed.
You can build one of these things into a Magic Marker case with a
nice sharp probe on the tip.
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