The 34-pin control cable for ST-506 interfaces can either have a twist or be straight through where you need to alter the HDD drive selects accordingly. The 34-pin control cable used on ST-506 interfaces doesn't care whether it lives in a PC PC/XT or PC/AT environment. Marty ______________________________ Reply Separator _________________________________ Subject: Re: ESDI Cabling Author: classiccmp(a)u.washington.edu at internet Date: 10/1/98 3:55 PM The AT MFM disk control cable (for ST506-like hard disks) certainly has a twist in it. This twist swaps over 2 of the drive select lines between the 2 drives, so they can both be set to the same drive number. I will have to get the manual if you want the exact details. I think the XT control cable does as well. I have an XT somewhere with 2 ST412 drives (in the 5161 expanasion box) but I'd have to dig it out to check if the cable has the twist. -tony ------ Message Header Follows ------ Received: from lists4.u.washington.edu by smtp.itgonline.com (PostalUnion/SMTP(tm) v2.1.9i(b5) for Windows NT(tm)) id AA-1998Oct01.155547.1767.67008; Thu, 01 Oct 1998 15:55:47 -0400 Received: from host (lists.u.washington.edu [140.142.56.13]) by lists4.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with SMTP id MAA19121; Thu, 1 Oct 1998 12:51:23 -0700 Received: from mxu3.u.washington.edu (mxu3.u.washington.edu [140.142.33.7]) by lists.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with ESMTP id MAA30654 for &lt;classiccmp(a)lists.u.washington.edu&gt;du>; Thu, 1 Oct 1998 12:49:00 -0700 Received: from post.mail.demon.net (post-11.mail.demon.net [194.217.242.40]) by mxu3.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with ESMTP id MAA26817 for &lt;classiccmp(a)u.washington.edu&gt;du>; Thu, 1 Oct 1998 12:48:59 -0700 Received: from [158.152.97.199] (helo=p850ug1) by post.mail.demon.net with smtp (Exim 2.03 #1) id 0zOoif-0004Wt-00 for classiccmp(a)u.washington.edu; Thu, 1 Oct 1998 19:48:58 +0000 Received: by p850ug1 id <m0zOmWg-000IyMC@p850ug1> (Debian /\oo/\ Smail3.1.29.1 #29.33); Thu, 1 Oct 98 18:28 BST Message-Id: <m0zOmWg-000IyMC@p850ug1> Date: Thu, 1 Oct 1998 18:28:23 +0100 (BST) Reply-To: classiccmp(a)u.washington.edu Sender: CLASSICCMP-owner(a)u.washington.edu Precedence: bulk From: ard(a)p850ug1.demon.co.uk (Tony Duell) To: "Discussion re-collecting of classic computers" &lt;classiccmp(a)u.washington.edu&gt; Subject: Re: ESDI Cabling In-Reply-To: &lt;199810010124.AA26688(a)world.std.com&gt; from "Allison J Parent" at Sep 30, 98 09:24:50 pm Content-Type: text X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN