Subject:	Re: slow floppy performance
To:	DJ's GPP mailing list <djgpp AT sun DOT soe DOT clarkson DOT edu>
Date:	Wed, 25 Nov 92 1:47:18 EST
From:	Stephen Turnbull <turnbull AT ecolan DOT sbs DOT ohio-state DOT edu>

> From: rezaei AT tristan DOT TN DOT CORNELL DOT EDU (Mohammad Ali Rezaei)
> 
> I was rather amazed at the slow disk performance, very noticable on
> floppies, of the fread command.

  [... stuff omitted ...]

> This worked great and I got tremendous increase in floppy performance.
> 
> Q1) do we want to change djcc to do this all the time?

Maybe.  Although I have my doubts about changing any FSF code if it's
not necessary.  One could have an alternative DJGPP-specific function
for efficiency.  BTW, I thought that Standard C had a global or member
(okbigbuf) to control the buffering behavior of FILE objects.  Maybe
that was C++ 1.x streams.

> Q4) read boils down to an int 21 call. My understanding of int 21 calls
> 	is that they are robust and reliable (across different versions
> 	of DOS and different devices.) by they are slow. So is there
> 	a way we can speed this up?

Probably.  But if so, I *really* have my doubts about putting the
changes in read() itself.  Unless you can ensure that they are robust
and reliable....
-- 
Stephen Turnbull
The Ohio State University, Department of Economics
410 Arps Hall, 1945 N. High St., Columbus, OH  43210-1172  USA
Phone: (614) 292-0654  Fax: ...-3906  Email: turnbull DOT 1 AT osu DOT edu

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