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From: dlyons@Apple.COM (David Lyons)
Newsgroups: comp.sys.apple
Subject: Re: Computer languages on the various Apple Corp computers
Message-ID: <31464@apple.Apple.COM>
Date: 23 May 89 23:41:56 GMT
References: <2821@puff.cs.wisc.edu> <10204@claris.com>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 37

In article <10204@claris.com> kevin@claris.com (Kevin Watts) writes:
[...]
>Sorry, but the 65816 is quite inadequate for high-level languages.  The main
>problem is it's severe shortage of registers, which is why it's NOT a RISC
>chip - they have LOTS of registers.  Yes, it does have stackframe support,
>but large data sets are extremely cumbersome - anything over 64K requires
>struggling like crazy to obtain any sort of reasonable performance, and
>because of the bank restrictions even 64K can be difficult to obtain.
>Crossing a bank boundary on a 65816 produces very messy code. [...]

It isn't all *that* bad...writing in high-level languages is certainly possible.

Crossing bank boundaries is not a problem.  Code segments can't do it, but
data segments can.  I really don't like global variables much at all in the
first place, so the Bank register doesn't bother me much.  I just use long
addressing when I really want to use global variables, and that way I don't
have to worry about setting it in content-draw procedures, etc.  Most of my
accesses are to direct page.

('course, in programs with a fairly small amount of code, I just put everything
in one segment and set B=K.)

My favorite addressing mode, by the way, is [xx],Y.  No bank restrictions, just
an offset from a 3-byte pointer on direct page.

> Kevin Watts        ! Any opinions expressed here are my own, and are not
> Claris Corporation ! neccessarily shared by anyone else.  Unless they are
> kevin@claris.com   ! patently absurd, in which case they're not mine either.

 --Dave Lyons, Apple Computer, Inc.          |   DAL Systems
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   My opinions are my own, not Apple's.