Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ptsfa!ames!rutgers!ll-xn!adelie!infinet!ulowell!page
From: page@ulowell.cs.ulowell.edu (Bob Page)
Newsgroups: comp.sys.amiga
Subject: Re: The secrets of the file system (was FillDisk)
Message-ID: <2112@ulowell.cs.ulowell.edu>
Date: 11 Dec 87 19:26:33 GMT
References: <6098@jade.BERKELEY.EDU> <2080@ulowell.cs.ulowell.edu> <2085@ulowell.cs.ulowell.edu> <22038@ucbvax.BERKELEY.EDU>
Reply-To: page@swan.ulowell.edu (Bob Page)
Organization: University of Lowell, Computer Science Dept.
Lines: 26

bryce@hoser.berkeley.edu (Bryce Nesbitt) wrote:
>DiskChange ought to be doing a ACTION_INHIBIT
>
>Now dos may follow up ACTION_INHIBIT with something as rude as 
>TD_CHANGESTATE, TD_CHANGENUM and/or TD_PROTSTATUS

It might not be DiskChange directly causing the non-standard
(trackdisk-specific) IO requests to be sent, but that's what is
happening.  If it's DOS that's turning ACTION_INHIBIT into calls to
TD_*, we've got a bigger problem than I thought, since any program
doing an ACTION_INHIBIT will cause this to happen.

>but none of those should give a harddisk.device fits.

Not if the writer of the harddisk.device knew that errant programs
might assume everything is a trackdisk, and send those commands to it.
What's TD_CHANGENUM to you might be HD_FORMAT to me!  That's why
they're listed as non-standard commands.  The DOS should not send
TD_* commands to any device other than harddisk.device, and neither
should user programs.

..Bob
-- 
Bob Page, U of Lowell CS Dept.  page@ulowell.edu  ulowell!page
"I've never liked reality all that much, but I haven't found a
better solution."		--Dave Haynie, Commodore-Amiga