Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!brl-adm!adm!Leisner.Henr@xerox.ARPA
From: Leisner.Henr@xerox.ARPA (Marty)
Newsgroups: comp.os.cpm
Subject: cp/m physical directory meaning
Message-ID: <2232@brl-adm.ARPA>
Date: Thu, 8-Jan-87 17:51:22 EST
Article-I.D.: brl-adm.2232
Posted: Thu Jan  8 17:51:22 1987
Date-Received: Fri, 9-Jan-87 00:00:21 EST
Sender: news@brl-adm.ARPA
Lines: 20

I'm writing a program which runs on a PC and can read and write CP/M
floppy/hard disks across a SCSI interface.

I can't seem to find a good spec which describes (preferably in
pseudocode or equations) how block shift, blockmask and extent mask are
used to build/access the directory.

I can figure out easily enough how to read/write cp/m SS/SD floppies,
but playing with hard disks with large group sizes gets trickier.  DRI
documentation concerning low level disk formats seems nonexistant.

Any pointers to magazine articles, books, etc. would be useful.

A set of algorithms in C would be great.

Any help would be appreciated.
 

marty leisner
leisner.henr@xerox.com