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From: jdb@mordor.UUCP
Newsgroups: net.arch
Subject: Re: PDP-11 "red and green" stack violation
Message-ID: <6562@mordor.ARPA>
Date: Tue, 22-Apr-86 21:27:40 EST
Article-I.D.: mordor.6562
Posted: Tue Apr 22 21:27:40 1986
Date-Received: Sat, 26-Apr-86 02:31:17 EST
References: <192@atari.UUcp> <164@brl-sem.ARPA>
Reply-To: jdb@mordor.UUCP (John Bruner)
Organization: S-1 Project, LLNL
Lines: 20

In article <164@brl-sem.ARPA> ron@brl-sem.ARPA (Ron Natalie <ron>) writes:
>> What is a "red and green" stack violation?  I've heard references to this
>> over the years, but no one has given me a satisfying explanation.
>> Does it exist only on obscure members of the PDP-11 family, or is it
>> a common, universal condition to which DEC has assigned a cute name?
>> 
>Actually it is red and yellow stack violation.  It isn't obscure PDP-11's
>just the big ones (45's and 70's).

Smaller (or maybe only older?) PDP-11's have a fixed stack overflow
boundary at location 0400.  I seem to recall that RSX-11M put its stack
down at the bottom of memory.  I'm not sure why they thought a stack which
extended down to the middle of the interrupt vector space (0 - 0777) was
ideal.

The yellow and red limits are 16 words apart.
-- 
  John Bruner (S-1 Project, Lawrence Livermore National Laboratory)
  MILNET: jdb@mordor [jdb@s1-c.ARPA]	(415) 422-0758
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