Obscure DOS question

[micheladam at theedge.ca]

How about using a later version of DOS, and having it masquerade
as 3.3 if need be? The version being reported to a program by the
OS can be changed on an individual program basis for compatibility
purpose, so you might remove the 512 file limit without too much
hassles.  I beleive MS DOS 5 and up have this facility. I certainly
remember using it for some AT&T STARLAN drivers way back...

Michel Adam
micheladam at theedge dot ca


----- Original Message -----
From: Vintage Computer Festival <vcf at siconic.com>
Date: Tuesday, March 29, 2005 8:22 am
Subject: Re: Obscure DOS question

> On Mon, 28 Mar 2005, Jim Leonard wrote:
> 
> > Vintage Computer Festival wrote:
> > > MS-DOS 3.3 has a limit of 512 entries in the root directory.  
> I have a
> > > need to put more than this.
> >
> > I seem to remember that the limit is actually 224.
> 
> It's definitely 512 on DOS 3.3.
> 
> > > Another question:
> > >
> > > When using the SUBST command in MS-DOS, you cannot aparently 
> substitute> > the C: drive.  I seem to recall that MS-DOS 6.0 
> allowed this, although I
> > > might be confusing that with the ability of LANtastic to 
> redirect the C:
> > > drive to a network drive.
> >
> > Checking 6.22 right here... works fine (I did "subst d: c:\"). 
> So yes,
> > you can.
> 
> Hmm, cool.
> 
> > > At any rate, what I'm trying to do is overcome the limit of 
> 512 file
> > > entries in an MS-DOS 3.3 root directory.
> >
> > SUBST won't help you do this unless you don't use a floppy at 
> all, like:
> >
> > 	subst a: c:\temp
> >
> > ...which works fine.
> 
> I'm not using floppies at all.  This is with hard disks.
> 
> > My question is:  Why?
> 
> I'm restoring files from VHS backup tapes.  The files were all 
> originallystored and backed up from the root directory.  On the 
> tapes I used to test
> my process, none had more than 512 files archived.  The backup 
> softwareonly restores *to the same exact drive and path* that the 
> files were
> archived from (in this case C:\).  I'm running into some tapes 
> that have
> more than 512 files backed up frm the root directory.  These were done
> back in the 1980s.  I can't figure out how they did it, but there they
> are.
> 
> Once a backup is made, you cannot add to the backup, so that's not how
> they did it.
> 
> Anyway, what I am trying to do so that we don't have to make two 
> runs on
> each tape (each tape takes 2 hours to dump) is to re-map the C: 
> drive to a
> directory so that we can overcome the 512 entry limit.
> 
> -- 
> 
> Sellam Ismail                                        Vintage 
> Computer Festival
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