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From: cur022%cluster@ukc.ac.uk (Bob Eager)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: When can you SYS a disk not originally formatted with /S?
Message-ID: <22371.2827c86e@cluster@ukc.ac.uk>
Date: 8 May 91 09:44:13 GMT
References: <1991May3.191723.24131@midway.uchicago.edu> <Ec8V7vK00awO06V0ZW@andrew.cmu.edu>
Organization: Computing Lab, University of Kent at Canterbury, UK.
Lines: 24

In article <Ec8V7vK00awO06V0ZW@andrew.cmu.edu>, dj1l+@andrew.cmu.edu (Demian A. Johnston) writes:
> When the first set of sectors on the disk are empty.  The Bootstrap
> MSDOS.SYS  (IBMDOS.COM) IO.SYS (IBMBIO.COM) need to be the first items
> on the disk.


Not quite right:

a) The first two directory entries on the disk must be empty, so that the
   first entry can be made IO.SYS (or IBMBIO.COM in the case of IBM and a
   few other manufacturers) and the second entry can be MSDOS.SYS (or
   IBMDOS.COM).

b) The MSDOS.SYS (IBMDOS.COM) file can go anywhere on the disk, and I don't
   believe it has to be contiguous except perhaps for very early versions.

c) The first cluster of IO.SYS (IBMBIO.COM) has to be the first cluster in
   the file space (cluster 2). Prior to DOS 3.3, the whole file  had to be
   contiguous; at DOS 3.3, the rest of the file is read in by the code in
   that first cluster.
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Bob Eager                | University of Kent at Canterbury
                         | +44 227 764000 ext 7589
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