Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!rochester!rit!ultb!lmb7421
From: lmb7421@ultb.UUCP (L.M. Barstow)
Newsgroups: comp.sys.apple
Subject: Re: Computer languages on the various Apple Corp computers
Message-ID: <861@ultb.UUCP>
Date: 31 May 89 20:54:48 GMT
References: <2075@umbc3.UMBC.EDU> <10211@claris.com>
Reply-To: lmb7421@ultb.UUCP (L.M. Barstow (674SPS))
Organization: Rochester Institute of Technology, Information Systems
Lines: 28


 In article <10204@claris.com> kevin@claris.com (Kevin Watts) writes:
>
>		[using the direct page as 'registers'] won't work
>at all if the direct page register is used to set up a stack frame, which
>is essential for a high level language and pretty much so in any sizable
>hand-coded assembler project.

Kevin also follows up in <10211@claris.com> with a pseudo-C compiled
example of a stack frame (very concise...nice, Kevin)

I believe there is a way around the vast majority of the direct-register
problem in the Stack relative adressing mode.  I'll admit, you can't
perform some operations with stack relative (shift operations are the
big one), and they are a little slower, but I think a register area
would be most helpful for improved performance, and would be willing to
assign the direct page to that purpose, using Stack relative for regular
variables in a stack frame (it was probably the reason for the adressing
mode anyway).

These ramblings do not imply knowledge of life, only practice with an
assembler.  I have been wrong before, I'm sure I'll be wrong again.

-- 
Les Barstow     LMB7421@RITVAX.BITNET
...rutgers!rochester!ritcv!ultb!lmb7421.UUCP
"I know you think you know what you thought I said, but
you don't realize that what you thought I said was not what I meant"