How to read recalcitrant floppies?

From: Mark <mark_k_at_iname.com>
Date: Thu Apr 29 13:44:11 1999

Hi,

On Sat, 17 Apr 1999 Ethan Dicks wrote:
> I am attempting to back up some floppies from a project I did a few years
> ago. The sets of 3.5" 1.44Mb IBM floppies have been stored in a box, in a
> cool and dry room. Out of one set of 12 and one set of 15 disks, I have four
> disks that have read errors that DOS won't get past, bad sectors and the
> like.
> ...
> Are there any tools to go divining on DOS floppies that work better than
> an endless succession of "R"etries? It's an all or nothing prospect; the
> first disk has the install file, the remaning disks have a chopped monolithic
> data file. If one disk can't be read, the whole set is fundamentally
> useless.

First, I take it you have tried reading the disks on different drives? If that
didn't help, using the fdread package *might*, but I doubt it.

You have an Amiga right? One possible solution, if you want to spend some time
on this, would be to write a program to read the raw data from the disk, then
MFM-decode and analyse the data and report/correct any errors. This could work
if the only problems are with sector headers. Or try creating disk images
using one of the various Amiga PC-disk-access packages, maybe one of those is
more forgiving? (CrossDOS, XFS, MultiDOS, etc.)


(Aside: since the Amiga disk controller is so versatile, it should be possible
to archive "all" copy-protected PC disks using a program such as MFMWarp.)


-- Mark
Received on Thu Apr 29 1999 - 13:44:11 BST