Z80 Computer

A brief description of the current components and problems in the design of a homebrew Z80 computer. Please see http://benryves.com/projects/z80computer for more information!

Category:

Science & Technology

Tags:

• Z80
• computer
• electronics
• BBC BASIC
• chip-8

[johnnyw66]

Have you tried Lua? I'm sure you could compile this for the Z80! Much as I use to love BBC Basic - Lua is a fantastic language - (open source).

[benryves]

@johnnyw66 I've never looked into what porting Lua would entail but I had assumed it would require quite a lot of memory. I have done some programming in it and did enjoy using it very much so agree with your review; the "Laserstrike for Zen X-Fi 2" video is a game I wrote for my music player in Lua. Have you looked into Brandy Basic for an open source version of BBC BASIC?

[johnnyw66]

Brilliant Ben! I think you said that you have 128Kb of Rom - can you tell us how you you address pass 64Kb? How easy is it to have the CPU back @10Mhz and use a NMI routine with a 2Mhz clock to memory dump the 'video' ram portion to the LCD?

[benryves]

@johnnyw66 Thanks - to address more than 64KB I used used a latch as an I/O register and connected some of its output pins to the address pins (A16 and above) that the Z80 couldn't drive directly. The Z180 has a built-in MMU and can address up to 1MB of memory, which would make things a bit easier. I ended up dropping this design (and LCD) for a different one entirely - see the "Mark 2" video on my channel.

[JDepptastic]

do you have schematics for this design??



[benryves]

@JDepptastic I'm afraid not, sorry. Is there any bit of it you had particular interest in?

[hbsorensen]

Cool circuit!

Great to see people still playing around with the "older" circuits - not everything in life needs 3 GHz :-)

Keep up the good work!

[JDepptastic]

wow that's the most amazing z80 project yet!!,

[benryves]

@dumyyyyyy Thank you very much for your kind comments! :-)

[dumyyyyyy]

congratulations for the computer! When y was a child, y had one of these.. loading games from audio tape. It was a HC91 and running BASIC language.Anyway , great job and respect for the effort you made. I know what it means to make a computer like this from scratch! I am a electronic hobbyist and i am aware about what effort you have done tu make something like this! Congratulations again! You have gained a new subscriber!