Path: utzoo!attcan!uunet!tektronix!sequent!mntgfx!mikes
From: mikes@mntgfx.mentor.com (Mike Stanbro)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Hard Disks: XT vs. AT
Message-ID: <1988Jul19.100226.737@mntgfx.mentor.com>
Date: 19 Jul 88 17:02:23 GMT
References: <6201@megaron.arizona.edu>
Organization: Mentor Graphics Corporation, Beaverton Oregon
Lines: 46

From article <6201@megaron.arizona.edu>, by cjeffery@arizona.edu (Clinton Jeffery):
> Hi people: for a year now I have been running an Atasi 3046 drive in my
> XT clone.  Recently I purchased an AT clone kit, planning on using the
> Atasi as its hard drive.  So far, the hard disk "fails initialization"
> and has resisted any attempts at low-level formatting in the AT.
> 
> So my question: what differences are there between the XT (e.g. WD WX1)
> controller and the AT (e.g. WD WA2) controller?  Don't most ST 506 drives
> work with either?  Are there any little jumpers I need to pull?
> 
> Any help would be greatly appreciated!
> -- 
> | Clint Jeffery, University of Arizona Department of Computer Science
> | cjeffery@arizona.edu -or- {ihnp4 noao allegra cmcl2}!arizona!cjeffery
> --

The question more appropriately should be "What isn't different?".

  * The WX1 is an 8-bit peripheral, the WA2 is a 16-bit.

  * The configuration setup on the WX1 is jumper selectable, on the WA2 it is 
    electrically programmed at boot-up using the disk-type data stored in the
    CMOS configuration RAM.

  * The WX1 is a hard-disk only controller, the WA2 is both a hard-disk controller 
    and a floppy controller.

I have installed a lot of hard disks in both XT's and AT's but never tried using 
a WX1 controller in an AT so I can't say that it is or isn't possible.  Even if 
it is possible to use the 8-bit controller, I suspect there is a significant 
performance difference between the two due to 2X data width and less wait states
for the 16-bit controller.

You can get a WA2 for about $140 if you shop around.


Mike Stanbro, Research Engineer                     (503) 626-1437
Mentor Graphics Corp., 8500 SW Creekside Place, Beaverton OR 97005
...!{sequent,tessi,apollo}!mntgfx!mikes   OR  mikes@pdx.MENTOR.COM
These are my opinions, & not necessarily those of Mentor Graphics.

-- 
Mike Stanbro, Research Engineer                     (503) 626-1437
Mentor Graphics Corp., 8500 SW Creekside Place, Beaverton OR 97005
...!{sequent,tessi,apollo}!mntgfx!mikes   OR  mikes@pdx.MENTOR.COM
These are my opinions, & not necessarily those of Mentor Graphics.