S-100 arch and CP/M

[Sharkonwheels]

...trying to put together an S-100 system.

Discussed a while ago, was my question on CP/M and and drives.

Here's the master question:

Can I take, say, a Vector Graphics chassis, pop in a North Star Z80 CPU card, a RAM card or two, and say a FD subsystem (card, cables, drive) with it's proper CP/M and expect it to work? Or is CP/M also looking for a specific CPU card as well?

for example, in the case above, using a cromemco soft-sector controller, proper 5.25" drives, and CP/M for the cromemco FD controller, would I need a specific Cromemco Z80 card? Or would an Imsai/Altair/Cromemco/North Star z80 CPU all be seen the same, and work the same?


Tony

 

[NobodyIsHere]

Sharkonwheels,

Personally, I would not expect an "off the shelf" CP/M to work without serious customization of the CBIOS.

All of the CP/M IO customization is contained in the CBIOS. It will have to be modified for all IO including the disk controller, serial ports, etc. Even memory maps can have an effect on CP/M so to do what you propose would require some very selective choosing of various IO boards in order for it to work.

Thats not to say impossible but very difficult I think. The NorthStar Horizon CP/M distributions work because they know where to expect IO and can write a beforehand which expects to find it at those locations.

I think a generic S-100 bus using a Z80 CPU board has a chance to work using a NorthStar CP/M distribution if you used a NorthStar Floppy Disk Controller and Serial IO board configured properly. Still, its not a sure thing.

Maybe some of the others who are more versed in CP/M installations can chime in. I know when I got CP/M to work on my Test Prototype system I had to write the CBIOS almost from scratch but did have other CBIOS's and help from experts to get it working.

Best of luck with your system and Thanks!

Andrew Lynch

 

[ziloo]

I have read similar discussions in other newsgroups. Although we have a
wealth of knowledge in VC Forum, another more focused place to inquire
about your specific question is "comp.os.cpm". I am sure this is old news
to you, but they have people with CP/M expertise and Z80 design
experience who frequently discuss very similar issues that you are stating.

Best Wishes

ziloo

 

[Thrashbarg]

Can I take, say, a Vector Graphics chassis, pop in a North Star Z80 CPU card, a RAM card or two, and say a FD subsystem (card, cables, drive) with it's proper CP/M and expect it to work? Or is CP/M also looking for a specific CPU card as well?

As said, you will have to make your own CBIOS or change an existing one to work with different I/O ports specific to the various cards you want to use. The CPU card shouldn't be important because it's just a CPU... unless it has I/O ports you want to support in CP/M.

The CBIOS I made for my 8080 computer is in the downloads section of my website (link's below) if you want to look at it. It's pretty lengthy because I've recently added a video card.