Date   : Fri, 04 Dec 1992 00:46:41 GMT
From   : concert!uvaarpa!murdoch!uvacs.cs.Virginia.EDU!sam2y@gatech.edu (Steven A. Moyer)
Subject: Porting CP/M

I have a question for those of you who have put CP/M onto a homebrewed
machine. Unfortunately, our university library has only 1 text on
CP/M and it is pretty much fluff with only hints at the insides so I
haven't been able to work this out for myself.

Apparently older peripherals, circa mid to late '70s, had less of a standard
logical interface than those currently in use.  Thus, BIOS was generally
not found in ROM (since this would only fit a given manufactures combination
of peripherals) and most folks rolled their own.  This, anyways, is the
claim of the text that I have.

While writing a device driver is no big deal, just tedious, it seems that
most people back then putting together a motherboard from here and a
disk driver from there, etc., were faced with a real 'chicken and egg'
problem.  Developing device drivers is all well and good when you
have a system to do it on, but you didn't have a system until you had a
bootable disk with the correct drivers.

So, what piece of the puzzle has my lack of adequate information left
me without?  How did those of you who put together your own system back
then handle this problem?

I'm curious because I'm putting together an old IMSAI as a 'just for fun'
project and I would like to get CP/M running on it.  I suppose I could
whip up an emulator for the IMSAI and my particular combination of peripherals
and get a floppy for the IMSAI compatible with my usual machine so that
I could get CP/M running and build a bootable diskette, but this seems
somewhat round about.

I'd like suggestions from others who have put one of these systems together
before. (other than to get a decent manual, I'm working on that ;-)

Thanks,

Steve


PS To those who replied with s-100 stuff for sale (from postings in other
groups): thanks! I'm getting around to answering everyone, but it was
quite a flood of mail.
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| Steve Moyer                    |       THIS SPACE FOR RENT         |
| Computer Science Department    |                                   |
| University of Virginia         |                                   |