Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!apple!oliveb!amiga!cbmvax!jesup
From: jesup@cbmvax.UUCP (Randell Jesup)
Newsgroups: comp.sys.amiga
Subject: Re: What controller to use with the A2000?
Message-ID: <6431@cbmvax.UUCP>
Date: 29 Mar 89 06:16:14 GMT
References: <16272@cup.portal.com>
Reply-To: jesup@cbmvax.UUCP (Randell Jesup)
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 21

In article <16272@cup.portal.com> Doug_B_Erdely@cup.portal.com writes:
>My friend has an A2000 and he is going to ditch his A2090 controller since
>there is no bad block mapout and its been nothing but problems. So he is
>looking for a new SCSI controller to purchase.

	Note that with a SCSI disk the DISK does the mapping, NOT the
controller.  Every time the disk is low-level formatted (aka preped), the
SCSI disk is supposed to test itself and map out all bad blocks found.  Of
course this destorys all info on the drive.  Some SCSI drives support
the Reassign_Block command, though not all, which allows mapping out on the
fly.

	Also, the A2090 has its own bad block mapping on top of the SCSI (since
it has to be there for st506.)  Note that it will not add bad blocks to it's
internal list of bad blocks, and probably shouldn't, since almost all bad blocks
are found on reads, and if you map it out you lose any chance of recovering the
data (like when my SCSI drive overheated and started getting read errors
everywhere, because the room was 85-90F.)

-- 
Randell Jesup, Commodore Engineering {uunet|rutgers|allegra}!cbmvax!jesup