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0 pointsmindcrime9y ago0 comments

Yeah, I'm pretty excited. I've wanted to do something like this for a long time, and finally quit dragging my feet. Well, I got as far as ordering some books and some of the components I'll need.

The first two things I'm planning to do are:

1. implement a Z80 test circuit that will let me just blink some LED's or whatever they do. This is apparently one of the most basic things you can do with a Z80 and doesn't require much in the way of supporting components and what-not.

2. Figure out how to write bytes to, and read bytes from, an EEPROM using an Arduino. I found a bunch of Youtube videos and websites on this topic, to use as resources.

Sometime after that, I'll start investigating what it takes to read a program off the EEPROM and execute it.

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tluyben29y ago· 2 in thread

1. Indeed; that requires only very basic components; I would recommend a cheap digiscope + analog scope so you need even less components to have fun. The z80 is so slow that you can use very cheap scopes.

2. I bought an 80s EPROM writer from a forum for E1 which I use for that; because it's so old (and slow), you can actually understand and measure what everything does.

jackhack9y ago

+1 on the cheap scope recommendation. Without seeing your signals, solving a problem with shoving bits around is (educated) guesswork. Nothing like struggling for days with a weird fault or corrupted xmit only to throw a scope on a bus line and see in a few seconds where the problem lies. (voice of experience speaking).

And here's the good part: These days, a basic scope is incredibly cheap!

Check ebay and/or amazon for a DSO138. It's a simple creature but ideal for a project such as a Z80. There are two variants of the DSO138 - kit form and pre-assembled. Prices are an astounding $25/$30 respectively.

Unless you just want to spend 4 hours soldering (not a bad thing), spend the extra $5 and get the prebuilt. And make sure it has the latest firmware (cleaned up some bugs, improved centering, and reduced noise).

And @mindcrime - please blog that project! I know I speak for loads of others when I say I'd love to watch your progress. I never get tired of seeing others do cool stuff I don't have time for anymore. :)

mindcrimeOP9y ago

I've been eying one of those Rigol DSO's that people seem to really like. They're not crazy expensive, but get pretty good reviews. I think I'll wind up getting a standalone frequency counter as well, at some point.

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