From: Jason Green <news AT jgreen4 DOT fsnet DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: 18-sector limit with biosdisk()
Date: Fri, 09 Feb 2001 12:31:29 +0000
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Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> wrote:

> On Wed, 7 Feb 2001, Jason Green wrote:
> 
> > > Well, many bioses will not boot with the 'compact' option, because they
> > > don't know how to deal with a full-track 21-sector read.  They can read
> > > one sector at a time up to track 21, but if you say, 'read 21 tracks to
> > > the buffer starting at track 0', they choke.  So, with LILO you have to
> > > NOT have the 'compact' option.  Now, in the case of the kernel loading,
> > > directly without LILO, maybe it is combining the reads the same way and
> > > failing that way?
> > > 
> > > -Tom
> > 
> > If I understand this correctly it means that certain BIOS
> > implementations limit the read buffer size.  On the other hand I could
> > just as easily have the wrong end of the stick... ;-)
> 
> Does this mean that if we bump the limit to 21 sectors, programs might 
> choke with som BIOSes?

Yes - unless you think it could mean something else.  If there is some
doubt then it would be worth to do a simple test before any serious
development work on libc.