Path: utzoo!utgpu!water!watmath!clyde!rutgers!sri-spam!ames!amdahl!nsc!voder!wlbr!pete
From: pete@wlbr.EATON.COM (Pete Lyall)
Newsgroups: comp.sys.m6809
Subject: Re: Suggestion for an OS9 utility
Keywords: Bad Disk Sectors
Message-ID: <1169@wlbr.EATON.COM>
Date: 22 Jan 88 00:08:42 GMT
References: <2265@ihwpt.ATT.COM>
Reply-To: pete@wlbr.UUCP (0000-Pete Lyall)
Organization: Eaton IMS, Westlake Village, CA
Lines: 45

In article <2265@ihwpt.ATT.COM> knudsen@ihwpt.ATT.COM (mike knudsen) writes:
>I'd like to find, or get help to write, a simple (?)
>utility that would read thru an entire diskette and
>find all the bad (as in unreadable) sectors and mark
>them as in-use on the sector allocation bitmap so that
>they would never be assigned to any future files.

Mike - 

    I wrote a little nasty tool several years back in B09 to do
    something similar. It reads all the sectors on the media
    (number is determined from LSN0), and barks at errors (optionally
    to a disk_error_log). In the event of a CRC error, it'll attempt
    to rewrite the sector to itself.. usually a recovery. It did not
    deallocate a sector from the free map, although bitmap operations
    aren't as tough as they look, and could semi-easily be retrofitted
    with 'syscall'. This is especially simplified by the fact that
    most everyone uses a clustersize of 1 bit = 1 sector.

    The code really needs to be cleaned up and rewritten, best
    probably if in C. I keep meaning to, but you know the drill...

    If you're volunteering to do just that, I'll be happy to mail you
    the code.

    Some other tips are that you get a *lot* better throughput if you
    read a track at a time:

    (i.e. read(diskpath, trakbuff, tracksize_in_bytes))

    If you get an error, *then* identify which sector of the track was
    offensive.

    BTW - what inroads are you making into OS9, Midi, and music? We
    (os9 forum) have a group of active MIDI junkies (self included)
    that are about to christen a MIDI driver, and some other stuff.
    Also, be advised that Lester Hands (Musica, Lyra, etc.) has been
    seduced by Level II (with a little gentle prodding *8^}), and is
    working on a windowfied version of OS9 Lyra.


-- 
Pete Lyall (OS9 Users Group V.P.)             Eaton Corporation (818)-706-5693
Compuserve: 76703,4230 (OS9 Sysop) OS9 (home): (805)-985-0632 (24hr./1200 baud)
Internet: pete@wlbr.eaton.com  UUCP: {ihnp4,scgvax,jplgodo,voder}!wlbr!pete