From: Baltissen, GJPAA (Ruud) (ruud.baltissen_at_abp.nl)
Date: 2004-12-10 13:55:01
Hallo allemaal,
I need some advice. At this moment I'm writing the ML for the macros for
programs meant to be run on the C64. If possible I'll try to use the code
already available on the C64.
For example:
...
var by : byte;
...
writeln(by);
...
The contents of by is converted to a floating point using onboard routines
and this FP is displayed on the screen, again using onboard routines. But
should I use these Kernal routines all the time?
Take the addition of two longints (= signed double word):
- there is a routine to convert a longint to FP
- there is a routine to transfer FAC to ARG
- there is a routine to add ARG to FAC
- there is a routine to convert a FP into a longint
But this last rountine delivers the result into the wrong order so I need my
own routine to correct this !!! (Anyone has an idea why? Routine can be
found at $BC9B.)
So I decided to make my own adder. The resulting routine needs only a few
bytes extra then when using the Kernal routines. But I'm quite sure that it
is much much faster.
At this moment I'm facing more of these dilemmas: what about AND/OR/XOR-ing
two bytes, should I use the original routines or make my own?
But making my own routines raises again some more questions: I have bytes,
integers, words and longints, do I have to create routines for every type?
The idea to solve this problem is to convert every type to longint, perform
the needed aritmetic and to convert back again. But this comes close to
converting them to FP. You see: dilemmas enough :(
Another subject: what is the best Basic compiler you know? I want to write
and compile some basic and equivalent pascal programs to compare the
resulting sizes. (And to see how they did it of course :)
Thanks for any input!
--
___
/ __|__
/ / |_/ Groetjes, Ruud
\ \__|_\
\___| URL: Ruud.C64.org
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