Re: Microsoft Z80 Card

[ziggy <ziggy@fakedaddress.com>]

In article <dvgk3p$vdj$1@merope.saaf.se>,
 pausch@saaf.se (Paul Schlyter) wrote:

> In article <441b5b3b$0$7748$9b4e6d93@newsread4.arcor-online.net>,
> Linards Ticmanis  <ticmanis@gmx.de> wrote:
> 
> >> 4 - does the apple CP/M work with SCSi drives? ( and the CFFA, if i 
> >> manage to get one ) or am i stuck with just floppies?
> > 
> > No idea, sorry. I'd guess not.
> 
> The standard Apple CP/M distribution supports only floppies, that's
> correct.  However, when compared to other OS'es of that time, CP/M was
> unusually versatile if you wanted to add a new kind of disk drive to
> it.  Get a copy of the CP/M Alteration Guide e.g. here:
> 
>     http://www.cpm.z80.de/drilib.html
> 
> There you'll find descriptions of how to correctly set up the disk
> parameter tables in CP/M's BIOS to make your new drive recognizable
> by CP/M.  To that, you must add code which actually accesses your new
> drive - naturally that is system specific and cannot be covered in
> a generic manual.
> 
> Formatting a new drive for CP/M is easy: just make sure all the
> sectors are there, then fill them all with hex E5 bytes.
> 
> CP/M 2.x is able to support disk volumes up to 8 MBytes large.  If
> your disk is larger than that, CP/M will be able to access only the
> first 8 MBytes of the disk.  Partitioning the disk may help here, but
> since CP/M knows nothing about disk partitions, you must implement
> that yourself in the code which is called by CP/M's BIOS.  It's
> probably most convenient to make each disk partition appear as a
> separate CP/M drive.
> 
> Finally, to have your modified CP/M start up nicely, you have two
> options: either write your modified CP/M to the boot tracks on your
> floppies.  Or run some programs which modifies CP/M in RAM after the
> normal CP/M boot has finished.

Ya, i know i can do that, however, my assembler skills are rather rusty, 
and im no where near that point again, yet.