Diff between 11/20 and 11/45?

Hi all, Dennis Ritchie has unearthed some really old Unix a.out executables from around 1st Edition - 2nd Edition period: see Distributions/research/1973_stuff in the PUPS Archive. [ Actually, I suspect his dates are a year off: they should be 1972 ] I've printed off the 1st Ed manuals from Dennis' web page, and I'm attempting to get my a.out emulator, Apout, to run these old binaries. I've got a few working. cat works. ls and date run, but sort of give strange outputs. 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. There is no source code with these binaries, so I can't use that to help debug the emulator. I do have the following processor handbooks: PDP-11 /20 /15 /R20 1972 PDP-11 /45 1973 PDP-11 /04 /34 /45 /55 /60 1978-79 I just thought I'd ask for pointers here before I hit them for details. Cheers, Warren Received: (from major@localhost) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) id LAA27104 for pups-liszt; Tue, 7 Sep 1999 11:10:31 +1000 (EST) Received: from henry.cs.adfa.edu.au (henry.cs.adfa.edu.au [131.236.21.158]) by minnie.cs.adfa.edu.au (8.9.3/8.9.3) with ESMTP id LAA27099 for <pups(a)minnie.cs.adfa.edu.au>au>; Tue, 7 Sep 1999 11:10:25 +1000 (EST) Received: (from wkt@localhost) by henry.cs.adfa.edu.au (8.9.2/8.9.3) id LAA12638 for pups(a)minnie.cs.adfa.edu.au; Tue, 7 Sep 1999 11:10:25 +1000 (EST) From: Warren Toomey <wkt(a)cs.adfa.edu.au> Message-Id: <199909070110.LAA12638(a)henry.cs.adfa.edu.au> Subject: KE11-A! (was Diff between 11/20 and 11/45?) To: pups(a)minnie.cs.adfa.edu.au (Unix Heritage Society) Date: Tue, 7 Sep 1999 11:10:25 +1000 (EST) Reply-To: wkt(a)cs.adfa.edu.au X-Mailer: ELM [version 2.4ME+ PL43 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-pups(a)minnie.cs.adfa.edu.au Precedence: bulk Hi all, I've just answered my own question. Reading thru the 11/20 processor handbook, I see the section on the extended arithmetic element, KE11-A, which is ``an option to perform multiplication, division, multiple position shifts and normalization significantly faster than software routines''. I also see that unit 1 lives at 777300 - 777316, and the date a.out executable does this: 230: TRAP 15 time syscall 232: MOV #177770,@#177314 240: MOV #47432,@#177300 246: ADD #5,@#177304 254: MOV #7,@#177300 262: MOV @#177302,@#177304 270: MOV #5,@#177306 276: ADD #40622,@#177304 304: MOV @#177304,320 . . . So it looks like I need to add KE11-A support to my emulator :-) Cheers, Warren