Received: (from major@localhost) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) id TAA10091 for pups-liszt; Thu, 9 Sep 1999 19:48:18 +1000 (EST) Received: from Zeke.Update.UU.SE (IDENT:2026@Zeke.Update.UU.SE [130.238.11.14]) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) with ESMTP id TAA10087 for ; Thu, 9 Sep 1999 19:48:09 +1000 (EST) Received: from localhost (bqt@localhost) by Zeke.Update.UU.SE (8.8.8/8.8.8) with SMTP id LAA22975; Thu, 9 Sep 1999 11:58:20 +0200 Date: Thu, 9 Sep 1999 11:58:19 +0200 (MET DST) From: Johnny Billquist To: Warren Toomey cc: Unix Heritage Society Subject: Re: Diff between 11/20 and 11/45? In-Reply-To: <199909062356.JAA12397@henry.cs.adfa.edu.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-pups@minnie.cs.adfa.edu.au Precedence: bulk On Tue, 7 Sep 1999, Warren Toomey wrote: > These executables were written for a PDP-11/20. Are there any significant > USER-MODE differences between the 11/20 and later PDP-11 models? I'm > thinking missing instructions, different addressing mode behaviour etc. As far as I can remember, there aren't any huge differences. However, some stuff behave differently in the 11/20. On the other hand, some stuff behave differently in just about every implementation... Condition flags on some instructions specifically. And the 11/20 might have had some limitations on using the PC which differed as well. I have a processor handbook for the "modern" -11s, which has a chart with all differences between different models. I started writing it down, to place in the PDP-11 FAQ, but haven't come that far yet... Johnny Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt@update.uu.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol