Forward To The Past - 5

Single Stepping

So far, there's no reason why things should not just work.  But what if there's a problem?  Last night I was trying to work out why one of my address outputs didn't work right, and it occurred to me that since the Z80 is essentially a static processor, it would be pretty easy to add a single-step clock to our design so far.

All this requires is a 74LS00 a Single-Pole Double-Throw (SPST) pushbutton switch and a couple of resistors.  Now, for each push of the switch we get one clock transition. 

I will update the main schematic soon to reflect this change, and provide a way of selecting either option without rewiring, but since I'm working on breadboards, this is not too big a challenge to change over at the moment.

Another option would be to use a very low speed clock.  We could either have a separate RC oscillator, or divide down the 8MHz signal to pretty much anything we like.

What would you rather see?

Comments

Popular posts from this blog

Recording weather with Arduino, Elasticsearch and Kibana 3

Auric: All about batteries

Recording weather with Arduino, Elasticsearch and Kibana