Minimal Z80

I mentioned a while ago in the Bar Sport "latest purchase" thread that I was buying parts and PCBs for a Z80 system. Well, that's working now, running Basic, a serial .hex file downloader, and Forth, so I guess I can move a report here... (Debugging the Forth implementation was especially "fun", since it involved switching assemblers as well as new hardware and no debugger...)

It uses an ATmega32A running arduino code (and the IDE) as the general purpose IO controller and bootstrap device...

Old thread Project Page
My github page with PCB design and Forth Source/hex
And Picture!!!:

You have done a nice job of it.
I remember the talk on Z80 based systems way back then, gosh, that was a while ago.

It's been a few decades since I last developed with a Z80 and wire-wrapping prototypes.
I only had assembler to use then as well.

You have modern SRAM on it too, beats 2114 or 6116 chips I think, yes ?

Well, I wonder if this will spark up a few of the other Z80 fans, Rob (aka GreyNomad) I expect he will also will be reaching for his drool cloth when he comes past here.

I'll check out your github then I guess :slight_smile:

I wonder what plans you have for the new board, anything in particular ?

Paul - VK7KPA

what plans you have for the new board

Well, I made the LED blink!
Normally, I'm not very into "retro" computer technology (nothing older than a PIC, anyway), but this design was clever and cheap enough to run with (well, perhaps not THAT cheap, after spending $30 on PCBs, but... I can make (have made) more than one! At my age, I have a bunch of friends who were like "My first job was programming a Z80..."; maybe I'll make them into gifts!)
In theory, a Z80 system like this is particularly interesting because it is so "RAM-rich" compared to most microcontrollers. Having 32k of flash and 2k of RAM is much different than having 34k (or more) of true vonNeuman RAM...