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From: brantley@coraid.com (Brantley Coile)
Subject: [TUHS] Query on PDP-11 assembly
Date: Wed, 30 Apr 2008 09:55:13 -0400	[thread overview]
Message-ID: <48187A41.80105@coraid.com> (raw)
In-Reply-To: <20080430115651.GA86539@minnie.tuhs.org>

In your example, -(sp) = r5; r5 = pc; pc = guestf.
Guestf will have to bump r5 as in consumes the parameters.
Rts r5 means pc = r5; r5 = (sp)+.

Hope this helps.

Warren Toomey wrote:
> All, I'm trying to write a PDP-11 disassembler for a.out files. I'm having
> trouble dealing with jsrs. Take, for example, the code here:
> http://minnie.tuhs.org/UnixTree/1972_stuff/s1/frag19.html
> 
> I can happily deal with the   jsr pc,do   type of jsr, but the ones
> involving r5 have me stumped, e.g.:
> 
> 	jsr	r5,questf; < nonexistent\n\0>; .even
> 
> It appears that data is being inserted into the executable directly
> after the jsr instruction. How does the rts which returns from the jsr
> know how much data to skip, and what is the involvement of r5 here?
> 
> Thanks,
> 	Warren
> _______________________________________________
> TUHS mailing list
> TUHS at minnie.tuhs.org
> https://minnie.tuhs.org/mailman/listinfo/tuhs



  reply	other threads:[~2008-04-30 13:55 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-30 11:56 Warren Toomey
2008-04-30 13:55 ` Brantley Coile [this message]
2008-04-30 14:41   ` Naoki Hamada
2008-05-01 23:47     ` Warren Toomey
2008-04-30 16:53   ` Milo Velimirovic
2008-04-30 17:00     ` Larry McVoy
2008-04-30 17:47       ` John Cowan
2008-04-30 17:59         ` Larry McVoy
2008-04-30 15:08 ` Carl Lowenstein
2008-04-30 16:20 James A. Markevitch

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