Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!asuvax!yendor!stefan
From: stefan@yendor.phx.mcd.mot.com (Stefan Loesch)
Newsgroups: comp.sys.atari.st
Subject: Re: DOES TOS 1.4 DO THIS?
Message-ID: <11358@yendor.phx.mcd.mot.com>
Date: 1 Aug 89 16:52:35 GMT
References: <8907260006.AA28980@ucbvax.Berkeley.EDU> <1625@atari.UUCP> <660@electro.UUCP> <1629@atari.UUCP>
Reply-To: stefan@yendor.UUCP (0000-Admin)
Organization: Motorola Microcomputer Division, Tempe, Az.
Lines: 23

In article <1629@atari.UUCP> apratt@atari.UUCP (Allan Pratt) writes:
>for writing to these bad sectors, it shouldn't happen.  If it does,
                                      ^^^^^^^^^ But it does
>perhaps the sectors in question are marginal: they formatted ok but
>subsequent accesses were bad.
  No. See below.
>
>It's also possible that I'm totally wrong and old TOS didn't mark bad
  I think you are :-)
>sectors correctly.  What version are you using?  (Original) TOS 1.0 or
>(Mega) TOS 1.2?
>
I have a 1040 for 3 years now and I noticed that strange behaviour long
ago. If you format a disk with bad sectors (DS) the format prg. reports
7XXXXX bytes free (less than the usual 726XXX !), so I assume it found
the bad sectors and marked them. If you now write to that disk, everything
seems to be OK, only if you try reading it again you get the infamous
"check your cable" message.
My conclusion: format sees and marks bad sectors, write doesn't care about
the mark.
By the way, I have 2-26-86 TOS.
regards
	Stefan Loesch 		uunet!asuvax!mcdphx!yendor!stefan