[comp.sys.atari.st] Interesting

UACE0@uhupvm1.BITNET.UUCP (03/02/87)

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Date:         Sun, 01 Mar 87 21:59:38 CST
From:         "University (of Houston) ACE (UACE)" <UACE0@UHUPVM1>
Subject:      Interesting
To:           ST Users <INFO-ATARI16@score.stanford.EDU>

Well, an interesting thing happened to my hard disk this weekend, I crashed
the D partition while using michtron utilities to recover a file.  I don't
know if the latest version fixes this, but I was upset non-the-less to find
out that recovering a file would crash the partition.

As it turns out, only the first sector was damaged, so a simple read rwabs from
drive E (which had the same size) to write rwabs on drive D fixed it.
However, some of the top level files were screwed up, and some of the files in
the directory I was trying to recover from were screwed up.  But I was able to
get drive D back online and save what I could before zeroing it out.  SOOOO...
If you have a bad partition, or get a bad partition on your hard disk, try
writing a little program which does a read RWABS from boot sector zero from a
partition of the same size and writing it to the boot sector of the bad
partition.  If this doesn't work, try one more sector, and keep trying one
more sector, for a few.  Chances are you will be able to recover some of the
STuff.  I will post a program which will do this, soon (like this week).

- Mike Vederman

dyer@atari.UUCP (03/03/87)

> If you have a bad partition, or get a bad partition on your hard disk, try
> writing a little program which does a read RWABS from boot sector zero from a
> partition of the same size and writing it to the boot sector of the bad
> partition.  If this doesn't work, try one more sector, and keep trying one
> more sector, for a few.  Chances are you will be able to recover some of the
> STuff.  I will post a program which will do this, soon (like this week).

Logical sector zero (in a partition) contains a standard floppy-like
prototype-BPB with only the fields BPS, SPC, RES, NDIRS, NSECTS and
SPF valid (see your Guide, "Boot Sectors", pp 58-60 in my edition):

	BPS	= 512
	SPC	= 2
	RES	= 1
	NDIRS	= 256+
	NSECTS	= #sectors in partition
	SPF	= (((NSECTS/2)+2)/256)+1

NDIRS is nondeterministic, but is >=256.  Word values (like SPF) are
stored in 8086 format.  16 bit FATs are always used.


The Rwabs() trick mentioned above should work unless the FATs and root
directories have been clobbered.  I supposed you could back them up to
floppy before you ran that Michtron utility....

-- 
-Landon Dyer, Atari Corp.	    {sun,lll-lcc,imagen}!atari!dyer

The views expressed here do not not
necessarily reflect those of Atari Corp.	Segments are for worms.

jmg@cernvax.UUCP (03/06/87)

In article <575@atari.UUCP> dyer@atari.UUCP (Landon Dyer) writes:
>
>Logical sector zero (in a partition) contains a standard floppy-like
>prototype-BPB with only the fields BPS, SPC, RES, NDIRS, NSECTS and
>SPF valid (see your Guide, "Boot Sectors", pp 58-60 in my edition):

What guide? Where can I buy it?

leavens@atari.UUCP (Alex Leavens) (03/09/87)

in article <448@cernvax.UUCP>, jmg@cernvax.UUCP (jmg) says:
> 
>>SPF valid (see your Guide, "Boot Sectors", pp 58-60 in my edition):
> 
> What guide? Where can I buy it?

  The HitchHiker's Guide to the BIOS, which is part of the Developer's
Kit.  You buy the Developer's Kit from us.  Contact Cindy Clavern at
Atari.

--alex @ Atari

BIX: alexl.          GEnie: ALEXLEAVENS         AtariCorp: 408-745-2006

jmg@cernvax.UUCP (03/12/87)

In article <621@atari.UUCP> leavens@atari.UUCP (Alex Leavens) writes:
>  The HitchHiker's Guide to the BIOS, which is part of the Developer's
>Kit.  You buy the Developer's Kit from us.  Contact Cindy Clavern at
>Atari.

I don't want the bl--dy developers kit. I want proper technical
documentation from Atari.

Quote from the editorial of a UK computing journal (serious):-

Another worrying sign is a survey of 2000 xxxx users carried out by
Marplan for xxxx, which showed that while they were more satisfied
with their suppliers in 1986 than in the previous year, they are
still far from happy with the quality of its documentation.
Documentation is not glamorous, nor is it a big moneyspinner for
manufacturers. But to the user it is all-important.

If suppliers want to sell more machines to a user base that has eaten
its fill of glamour and jargon, they will have to start to concentrate
on improving services like documentation and maintenance.