23 Jan
2009
23 Jan
'09
12:53 p.m.
Subject: CP/M 2.2 Sector Translation Question
From: "ROBO5.8" <robo58 at optonline.net>
Date: Thu, 22 Jan 2009 18:30:54 -0500
To: "'General Discussion: On-Topic Posts Only'" <cctech at
classiccmp.org>
Hi,
I'd like to know if CP/M 2.2 is "Zero" biased when it comes to Sector
Translation. Since v2.2 supports Blocking/Deblocking I would assume it has
to be. I've looked at lots of code examples via Google and searched the
documentation but I cannot find a statement to that effect.
The short answer is yes.
Asking it another way: The Sector Translation routine is passed the
requested sector number in Registers B&C. Does CP/M request Sector 0 or 1
when it wants the first sector on any track.
Zero, Zed, 0.
It's up to the bios to:
A)translate that to a physical address,
B) do what is needed for sector skew
C) deblock if required.
Allison
Thanks Robo