newbie building a scratch-built computer

[Chuck Guzis]

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.

Cheers,
Chuck