home made z80 computers

[blackbeard]

so i've gotten this thing for working with old (make that ancient) hardware including my atari 2600, mac classic II, Amiga ect. and i've been really peaked by all these Zilog Z80 and Motorola 68000 based home brew computers. what i was thinking is that id like to build a Z80 based computer (mostly because of it's following and that it's still used today) running CP/M but what i was wondering was where to start? i don't mind getting an eprom programmer as well as any other building gadgets i need but i don't really want to just copy an existing design. i imagine a good place to start would be getting a working knowledge of Z80 assembly but i have no idea where to download an assembler. anyone have tips (aside from saying not to bother) where i should start?

[GearMotion]

I would have to dig a bit, but I think I have an assembler. I could get it to you.

Edit: here -> http://john.ccac.rwth-aachen.de:8000/as/

Also Steve Ciarcia published some Z80 and/or Z180 projects. If I'm not mistaken Circuit Cellar is reprinting a lot of those old books.

[billhowl]

Z80-ASM
http://wwwhomes.uni-bielefeld.de/achim/z80-asm.html
Software Development Tools for Z80 Family
http://www.z80.info/z80sdt.htm

[GearMotion]

Good work, Billhowl!

I wish that all of my old z80 schematics were digitized. I'll bet most of the paper has yellowed.

[blackbeard]

awesome i'm dling all those! the good thing about the Z80 is that they still produce it in a 40 pin dip. i can't find the 68000 in anything but smd plc or pga package. if you do find those z80 schematics you should deffinitely scan them!

[GearMotion]

awesome i'm dling all those! the good thing about the Z80 is that they still produce it in a 40 pin dip. i can't find the 68000 in anything but smd plc or pga package. if you do find those z80 schematics you should deffinitely scan them!

I'd be willing to mail to you a couple of z80 CPUs, as well as a PIO and DMA chip if you are willing to pay for the postage. I know where the chips are easily, but the old project documentation is probably well buried.

There are good schematics and a TON of info at that link Bill provided: http://www.gaby.de/z80/

[waltr]

I have a bunch of the older EPROMs with the UV window. Maybe even some old static RAMS and Intel timers, IO expansion and processors.
Just need to do some digging to find them.

Some offer as GearMotion's if you want them.

I guy I work with has a collection of old computers that he is considering departing with. If you might be interested let me know and I'll ask him to contact you.

I cut my digital teeth on an RCA Cosmac1802, went to an 8080 then a Z80 running CP/M. I wrote my own assembler back then but no longer have any of that code. Great times.
Good luck and have fun.

[Soeren]

Hi,

A couple of my friends and I (Informally known as "The Bartender, The Squatter and The Rocker" - hey, "The Three Musketeers" were taken ) build Z80 based Nascom computers back in the seventies and one of us (not me) actually put up lots of schematics, pictures and stuff on it on his website.
Check out MyPlace.nu the bottom link is a wealth of info about the stuff we played with then (and the upper link will probably interest a lot of people here as well, since Jesper really likes AVRs).

[blackbeard]

thanks for all the links guys! i actually happen to have a z80 computer that i never knew about before, my ti-83+ calculator. it should make for good practice in assembly before i actually get down to building my own device.

[lemontree]

The z80 has a really nice assembly language instruction set.  It is a pity that chip architecture was not developed very much.  Many great things fell to the wayside as Intel's marketing bulldozer plowed through.  A 32 bit z80 with 16 registers and something like the x86 SSE instructions would be great.  My dream would be a z80 based Larrabee chip ( http://en.wikipedia.org/wiki/Larrabee_(GPU)). Ha, ha Intel made a mess of it. The SSE type instructions are good for many types of high performance computing but are a serious mismatch for graphics processing.  Hopefully Intel will be forced to release it at a low price point.
Maybe a good place to start would be to look up information about programming the ZX spectrum which was a very popular home computer in the UK and Ireland in the 1980's that used the z80. There is very much code available for it on the internet: eg. (http://www.users.on.net/~tonyt73/TommyGun/ 

There is an assembler here: http://retrospec.sgn.net/game-links.php?link=z80asm
I don't know if it is good or not.

[negroslim]

lol i helped get all the equipment out at the 2 zilog fabs in idaho for shipment to the overseas buyers.