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Path: utzoo!watmath!clyde!rutgers!cbmvax!grr
From: grr@cbmvax.UUCP
Newsgroups: comp.os.minix
Subject: Re: Minix and compiler models
Message-ID: <1377@cbmvax.cbmvax.cbm.UUCP>
Date: Mon, 9-Feb-87 03:40:40 EST
Article-I.D.: cbmvax.1377
Posted: Mon Feb  9 03:40:40 1987
Date-Received: Tue, 10-Feb-87 04:30:36 EST
References: <966@ulowell.cs.ulowell.edu> <1565@cit-vax.Caltech.Edu>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Distribution: world
Organization: Commodore Technology, West Chester, PA
Lines: 18
Keywords: stacks

In article <14659@amdcad.UUCP> rpw3@amdcad.UUCP (Rob Warnock) writes:
>
>To my knowledge, the PDP-11 was the first machine in which stacks went
>the "wrong" way (from the "traditional" point of view). Later, people
>figured out that it made more sense on a 360 for the stacks to go the
>other way.
>Rob Warnock Systems Architecture Consultant

To save beating around the bush, one good reason for having stacks grow
down is that many architectures do not support signed indexing off registers.
This makes it difficult to access things pushed up on the stack by using
stack pointer relative addressing.  Of course you can always add a frame
pointer, but that's another register down the tubes and you usually don't
have that many to start with...
-- 
George Robbins - now working for,	uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)