[net.micro] FIX FOR AT DISK PROBLEMS

turek@brl-tgr.ARPA (C. A. Turek <turek>) (01/31/85)

 In the 7 Jan 85 issue of EE Times there is an article describing a
software "fix" for the IBM AT's fixed disk problem. The product is
called "DFixer" and claims to cure the bad sector problem with a 
"simple one-time running of the program".

 The program is a product of Interactive Data Corp. division of Chase
Manhatten Bank. { Looks like everyone is getting into the act! (:-)} It
is available from:

		MicroWay Distributors
		Kingston, Mass
		(617) 746-7341

		Price: $149 US

			TUREK@BRL

** Ref:7 Jan 85 EE Times, Pg. 44  "Software Solution Is Claimed For "Serious"
IBM PC AT Errors" by Richard Doherty

CSTROM@SIMTEL20.ARPA (02/03/85)

I had a recent conversation with a principal of a firm that purchased
about six 20Mb CMI hard disks (the same unit as is used in the AT) to
investigate using them in Zenith Z-100 machines. After extended
testing, all of the units failed - bad sectors spontaneously
appearing, and he returned them to the distributor.

In other words, according to this fellow's experience, the AT hard
disk problems are traceable to defective hardware, so it would be
difficult to imagine that a $149 program could repair things.

-Charlie

john@hp-pcd.UUCP (john) (02/08/85)

<<<

  I suspect the program works along the line of:

<patient> Doc, It hurts when I do this.

<doctor>  Don't do that.

In other words it may just look for the sectors that have failed and mark
them so that the system will not use them. That works in cases where the
problem is a bad spot on the media.

John Eaton
!hplabs!hp-pcd!john

jmsellens@watmath.UUCP (John M Sellens) (02/11/85)

The way I heard it:

For a few versions, DOS has not marked bad sectors properly.  It marked a
couple of sectors in the area of the bad sectors as bad, when they were
actually good, and left the bad sectors unmarked.  (Now remember, this is
just "what I heard", though I did hear it from a quite reliable source.)

The $149 fixer program (according to the article I read) marks the bad
sectors properly.

Perhaps this problem is only arising now due to the new style/brand of
hard disk and the possibility (fact?) that these disks have more
bad sectors, and hence, more chance to get hit.

Personally, I think $149 is a lot of money, but why not charge what the
market will bear???

John

johnl@ima.UUCP (02/11/85)

Sorry to report that although DFixer does what it's supposed to do, it is
not the long-sought fix for PC AT disk problems.  DFixer is just the thing
when you have disks with marginal spots on the platters.  Unfortunately, the
problem with AT disks is looking increasingly like a design flaw in the
per-drive electronics, and DFixer can't fix that.

I hear that the guy who wrote DFixer thinks that you can tell real marginal
spots from the AT's phantom ones, and is working on a new version of DFixer
that takes this into account.

John Levine, ima!johnl

PS:  As has been suggested, DFIxer knows about the DOS file format and can
be run quite safely on a disk with data on it.  If it finds that a sector
that is in use is bad, you lose, but you already lost anyway.