Date   : Mon, 29 Dec 2008 01:54:21 +0000
From   : jgh@... (Jonathan Graham Harston)
Subject: Using stack page for temp vars

"Alex Taylor" wrote:
> this (even though I was in my teens at the time). I'm not sure if this
> counts though, it was a tiny piece of machine code called from a BASIC
> program - is that the same, or does that not count because it's called
> from within BASIC?
 
Correct, it doesn't count. &70-&8F are reserved /by/ /BASIC/ for
use by machine code that is /called/ /from/ /BASIC/.
 
Too many people people interpreted that as reserved for use by
machine code. Full Stop. And so when that machine code was called
by something other than BASIC unexpected effects occured.
 

-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
RISC OS Choices System - http://mdfs.net/Software/RISCOS
PDP-11 BBC BASIC development - http://mdfs.net/PDP11/BBCBasic/blog