Diff between 11/20 and 11/45?

[wkt@cs.adfa.edu.au (Warren Toomey)]

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 at 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 at minnie.cs.adfa.edu.au>; Tue, 7 Sep 1999 11:10:25 +1000 (EST)
Received: (from wkt at localhost)
	by henry.cs.adfa.edu.au (8.9.2/8.9.3) id LAA12638
	for pups at minnie.cs.adfa.edu.au; Tue, 7 Sep 1999 11:10:25 +1000 (EST)
From: Warren Toomey <wkt@cs.adfa.edu.au>
Message-Id: <199909070110.LAA12638 at henry.cs.adfa.edu.au>
Subject: KE11-A! (was Diff between 11/20 and 11/45?)
To: pups at minnie.cs.adfa.edu.au (Unix Heritage Society)
Date: Tue, 7 Sep 1999 11:10:25 +1000 (EST)
Reply-To: wkt at 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 at 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