Re: CBM900 hard disk timeout

From: William Levak <wlevak_at_SDF.ORG>
Date: Tue, 26 Aug 2014 03:47:42 +0000 (UTC)
Message-ID: <Pine.NEB.4.64.1408260330250.1666@faeroes.freeshell.org>
It's been a long time since I worked on drives like this.  There are two 
kinds of format.  Normal high level format and low level format.  Low 
level format can sometimes be done from BIOS, but sometimes it was done 
from a routine on floppy disk.  I remeber that at least some Western 
Digital drives did the low level format from routine on floppy disk.

Most commands from the disk controller assume a low level format.  If the 
low level format is corrupted, it returns read errors.

If the first sector on the disk is bad, nothing can be done.  If you get 
read errors on sector 2, you can set sector 2 bad in the low level format and 
bypas it.

If you cannot do a low level format, you have mechanical or electrical 
problems.

There are utility programs that will read any sector on a hard drive 
directly, ignoring the directory and partition tables. I don't have one 
that works on SASI drives.



wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

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Received on 2014-08-26 04:00:02

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