Date   : Sun, 02 Apr 2006 12:10:17 +0100
From   : Fragula <fragula@...>
Subject: Re: 'Sector not found' - disc copyable?

Hi Neil!

neil f wrote:
> I'm trying to rescue some control software from an old 5.25"
> disc before it heads for magnetic heaven. It's a 40 track DFS
> disc which I presume has copy protection - hence the 'sector not
> found' error when I try to back it up. 

Is the software working ok? I ask to figure whether this is potentially
copy protection, or maybe a duff disk.

> Is there a way around
> this using available ROMs or whatever? 
If its copy protection, and using the good old "check for duff sector"(
which is usually an unformmated track or somesuch or "read deleted data"
(latter for which you need a real 8271) tricks, yes.

There are a couple of programs, some on ROM, some disk based. I'll try
to remember the names. "Enigma Disk Imager" was one that did most stuff
and was IIRC out in public circulation, for sale etc.

Another (disk-based BASIC, with a small amount of assembler) program
called "Copy Really All" did almost, if not all of,  everything. (i mean
in terms of FM single density disks here, its an 8271-specific program)
but I'm not sure whether that was out in circulation, or for that matter
whether I have it myself (probably!) or just used it elsewhere. (err..
got a few thousand floppies here, and fading brain cells.)

> I'm trying to archive it
> to hard disc using a dual 5.25"/3.5" drive and DFSreader on an
> RPC.
Hmm.. That could be problematic. The RPC doesn't have an 8271.. Now
here's the real question then, can you /run/ the program under an
emulator on the RPC? if you can, then its not using Read Deleted Data,
so its probably just a matter of finding a perfectly blank (i.e.
formatted at double density will kid a single density read most times)
then getting the format down with the unformatted tracks in the right place.

If on the other hand the disk is flakey, you have a larger problem.

Cheers!

M.