Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcrsys!tony
From: tony@mcrsys.UUCP (Tony Becker)
Newsgroups: comp.unix.sysv386
Subject: Re: MicroPort Unix V/386
Message-ID: <15@mcrsys.UUCP>
Date: 5 Oct 90 13:27:16 GMT
References: <1071@digi.lonestar.org>
Lines: 57

From article <1071@digi.lonestar.org>, by mfrohman@digi.lonestar.org (Matthew Frohman):
> I am using MicroPort's implementation of Unix (sys V/386).
> ...
> However much I
> allocate, it place DOS as the first partition, starting at 1,
> with the Unix partition following.

This is a DOS thing, It must be the first partition.

> 
> My question is, according to the documentation, NO partition
> should begin at 0 or 1.  That is reserved for something else.
> I see no way to specify where to begin the partition.

The first (0) sector (not partition) is the boot sector,
followed by the fdisk info, I believe. Partitions don't
start until the second track, which depends on your drive's sectors/track.

> It IS causing a problem, because after I install Unix, then
> go back to DOS and format the DOS drive and set it as the
> active partition, the next time I turn on my computer, the
> boot sector has been wiped out and FDISK says that there are
> NO partitions.

Gotcha!

1) make sure you don't allocate more then 32Mb (dos limit) of cyls to
   the Unix partitioner.

2) format the dos partition with dos 3.21-3.3 only.
   DOS4.01 may over-write the UNIX fdisk info.

3) DO NOT change the fdisk info with ANYTHING other then the original
   program, in this case, the UNIX partitioner. Note that if you change
   from Unix to dos as the active partition, you can't get back.

4) if you must boot dos, use a floppy. set up an autoexec.bat on the dos
   partition that sets the path and COMSPEC to C:...

This feature? is do to the fact that the boot sector anf fdisk info are
tied together AND that microsoft changed them from rev to rev of dos.
for the sake of argument the Microport's partitioner is DOS 3 compatible.
by sys-ing or fdisk-ing from dos, you run the risk of confusing either
the boot code, or the fdisk info it uses.

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| \      / |     /=|     /=|      Tony Becker           MCRSYS Florida
 \ \    / /       ||      ||      uunet!mcrsys!tony     (813) 799-1836 (voice)
  \ \  / /        ||      ||
   \ \/ /         ||      ||      Opinions expressed are my own, and don't
    \  /          ||      ||      necessarily reflect those of any other
    /  \          ||      ||      members of my species.
   / /\ \         ||      ||        -It's nice to live in a society where this
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