Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!decwrl!shelby!neon!kaufman
From: kaufman@Neon.Stanford.EDU (Marc T. Kaufman)
Newsgroups: comp.sys.mac.programmer
Subject: Re: How to tell if a volume is a floppy drive?
Message-ID: <1990Sep3.165151.29088@Neon.Stanford.EDU>
Date: 3 Sep 90 16:51:51 GMT
References: <3900@wucc.waseda.ac.jp> <690@dbase.A-T.COM> <12229@hoptoad.uucp>
Organization: Computer Science Department, Stanford University
Lines: 18

In article <12229@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes:
>In article <690@dbase.A-T.COM> cy@dbase.UUCP (Cy Shuster) writes:
->Always clear out your PB blocks: before every call!

>No offense, but I think that's terrible advice.  All you have to do is
>set the particular parameters listed as significant in the call.  The
>arrow is only deceptive in the case of ioNamePtr, which is sometimes
>listed as a left arrow only, even though you need to set it
>meaningfully on entry.

You should also zero the parameters that are significant in the call, even
if they are NOT listed in IM-(4-5).  Two that come to mind are ioVersNum and
ioMisc.  Given that not all significant parameters are listed in the
documentation, I have taken to using a fast BlockZero routine to zero the
parameter block.  The overhead of doing that is MUCH less than either the
file IO time or the Debug time.

Marc Kaufman (kaufman@Neon.stanford.edu)