Path: utzoo!attcan!uunet!cbmvax!jesup
From: jesup@cbmvax.UUCP (Randell Jesup)
Newsgroups: comp.sys.amiga.tech
Subject: Re: 2090A speed
Message-ID: <5522@cbmvax.UUCP>
Date: 16 Dec 88 21:57:36 GMT
References: <14015@cisunx.UUCP> <1135@esunix.UUCP> <9472@gryphon.COM> <183@sns.UUCP> <5507@cbmvax.UUCP> <328@b11.INGR.COM.>
Reply-To: jesup@cbmvax.UUCP (Randell Jesup)
Organization: Commodore Technology, West Chester, PA
Lines: 33

In article <328@b11.INGR.COM.> jim@b11.UUCP (Jim Levie ) writes:
>1) SCSI maps out bad blocks when the low-level formatting is done and 'prep'
>   does this.

	Yes, and in fact you don't even normally have to enter them, since the
SCSI controller should map them out all by itself (that's why it takes so long -
it's testing every sector).

>2) 'prep' only sets up the first 2 cylinders "where bad block info ..."
>   is stored for ST506 drives and prep wants the user to enter the bad
>   blocks in terms of head, track, and BFI.

	Quite true.  It reserved 2 cylinders for SCSI drives as well.

>3) The DOS format can do a read and write of every sector.

	Will do so, unless you use the 1.3 QUICK option.

>The question is does format add to the badblock information for SCSI or ST506
>drives?  It would seem to me that one of the things either format or some
>other utility should do is to find and report badblocks that are present on
>hard disks and also update the bad block data on the drive. When the bad blocks
>are reported they should be in a form suitable for input to "prep' to avoid
>having to scan for them in the future.

	Actually the idea is that when format is formatting and testing the
tracks, if the driver notes an error it should automatically map out that
sector, and add it to the list of bad blocks at the beginning of the drive.
Similar things happen with SCSI.

-- 
You've heard of CATS? Well, I'm a member of DOGS: Developers Of Great Software.
Randell Jesup, Commodore Engineering {uunet|rutgers|allegra}!cbmvax!jesup