Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!think!snorkelwacker!bloom-beacon!mcgill-vision!mcgill-vision!panisset
From: panisset@mcgill-vision.uucp (Jean-Francois Panisset)
Newsgroups: comp.sys.ibm.pc
Subject: Re: AT&T PC6300-compatible hard disk
Message-ID: <1990Feb23.004759.24730@larry.mcrcim.mcgill.edu>
Date: 23 Feb 90 00:47:59 GMT
References: <2587@intvax.UUCP> <1075@nems.dt.navy.mil>
Sender: news@larry.mcrcim.mcgill.edu (Usenet File Owner)
Reply-To: panisset@Moe.McRCIM.McGill.EDU (Jean-Francois Panisset)
Organization: McGill Research Centre for Intelligent Machines
Lines: 48

In article <1075@nems.dt.navy.mil> scherer@dtrc.dt.navy.mil (Doug Scherer) writes:
>In article <2587@intvax.UUCP> novak@intvax.UUCP (James L. Novak) writes:
>>A good friend has an early AT&T PC6300 (XT-clone) and wants to finally
>>join the real world and add a hard drive.  The problem is that everyone
>>he calls (mail order places) won't guarantee that an add-on drive/adapter
>>will work.  I know I used such a machine with a hard drive in school, but
>>don't remember anything about incompatibility problems.  Can anyone
>>enlighten me about problems and controllers/disks that will work.  Give it
>>to me techincal-I can translate for my MBA friend.
>    James,
>	Western digital XT disk card (WD1004A WX1) and I believe XTGEN
>are not compatible with the main ROM Bios in AT&T 6300 and AT&T 6300T 
>machines but can be altered to work.  To make it compatible you need 
>to disable the Bios on the disk controller by placing jumper resistor 
>at R23 and check that integrated circuits U7 and U8 are NOT installed.  
>When you do a low level format follow the directions AT&T gives you 
>not the western digital as the controller will no longer respond to 
>DEBUG.
>
>    I got this info from a Western Digital Tech. manual and have not
>tried this myself.
>
>    If anyone else hasaanymore input please post.
I used to have an Olivetti M-24, and since the AT&T 6300 was an Olivetti
with an AT&T logo on it, what I will be saying should apply (actually,
the BIOS in the 6300 still had the Olivetti name in it...).
The point is that you should first upgrade your BIOS ROM to version
1.43, if that's not already done. Among other goodies, this will
let you upgrade to EGA/VGA with less pain (still a lot involved, though).
The point is that the Olivetti BIOS has the HD control code built in.
Fortunately, version 1.43 defines one of the dip-switches to let you
disable this code. You can then use ANY XT-compatible HD controller
with a built-in BIOS without a conflict with the Olivetti BIOS.
I was able to install an Adaptec RLL controller in this way: the 
documentation for the Adaptec tells which switch to flick.

The BIOS upgrade to 1.43 is available from AT&T: it involves swapping
a couple of EPROMs. If anyone is interested in further details, send
me direct e-mail since I don't usually read c.s.i.p... I also
have a PD program to display the switch settings (with meanings)
of your AT&T: I could mail it to anyone who asks for it...


--
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Jean-Francois Panisset                       "Oui Allo!"
INET: panisset@larry.mcrcim.mcgill.edu       Madame Brossard, 1988
UUCP: ...!mcgill-vision!panisset