Minimal CP-M SBC design - test-drb@ccmp.vtda.org

11 May 2008

...

Subject: RE: Minimal CP-M SBC design
   From: "Barry Watzman" <Watzman at neo.rr.com>
   Date: Sun, 11 May 2008 11:16:18 -0400
     To: <cctech at classiccmp.org>

RE: "1.4 really didn't even do a DISK bios, it was embedded in the bdos.
the bios for 1.4 was only terminal, punch reader and printer IO.  Yes, it
was a pain to interface any new disk to it."

Allison, that is simply not true.  The diskette format (DPH and DBP) was
imbedded in the BDOS, but the disk I/O was in the BIOS, more or less like
2.x. 
Right and sorta right.

When you get down to it thats nearly as bad. But your right the hardware
was tweekable but the hardware was always assumed to be 8" SSSD in the end.
Being able to easily alter the media dimensions (DPH and DPB) allowed for 
larger media and more varied media.

Allison