Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!sun-barr!texsun!texbell!killer!chasm
From: chasm@killer.DALLAS.TX.US (Charles Marslett)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Need information on double-density SIO commands
Summary: Make sure you issue SIO commands, not DISKIO
Keywords: R W P DCOMND DBUFLO/HI
Message-ID: <8280@killer.DALLAS.TX.US>
Date: 5 Jun 89 05:17:17 GMT
References: <7097@c3pe.UUCP>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 19

In article <7097@c3pe.UUCP>, charles@c3pe.UUCP (Charles Green) writes:
> Now that I have an Atari drive that can read and write 256-byte sectors, I'd
> like to try accessing floppies from a CP/M machine in our office, which can
> write 40-track, single-sided, double density 256-byte sectors.  However, I
> haven't been able to successfully use SIO to read the sectors.

> So, can anyone shed some light on this issue?  Thanks for any information...
> -- 
> {decuac.dec.com,cucstud,sundc}!c3pe!charles	ex::!echo Boo:

You should be able to do that (I once wrote an ATR8000 "driver" that allowed
it to read/write 128-byte 1050-double-density disks, and another than read
1024-byte CP/M disks).  The major gotchas are (1) use $E459, not $E453 (the disk
handler), since $E453 code resets the length to 128 bytes before doing anything,
and (2) make sure you set the drive to double-density mode (if you need to) --
this depends on the type and generation of the drive . . . they're all different

Charles Marslett
chasm@killer.dallas.tx.us