[Coco] Assembler Source file for the CoCo ROMs

jdaggett at gate.net jdaggett at gate.net
Mon Oct 25 21:08:53 EDT 2010

On 24 Oct 2010 at 13:24, tim lindner wrote:

> tim lindner <tlindner at macmess.org> wrote:
> > This reminded me of a little project I started a while back.
> > 
> > I transcribed the Unravelled serise to produce re-assembable source
> > files for the various BASIC ROMS: Color, Extended, Disk and Super.
> > 
> > http://tlindner.macmess.org/?page_id=360
> > 
> > They assemble under Mamou, but that shouldn't stop anyone from porting
> > it to a different assembler.
> I wanted to list some idea someone could run with now that the source is
> avaiable:
> 1. Compact BASIC. Try to squeeze it even tighter that it already is.
> Shove it as high in memory as you can and set the program RAM size
> higher that $7000.
> 2. Integer BASIC. Strip all of the floating point routines and replace
> them with integer versions. Result: BASIC program will have a smaller
> RAM footprint and will execute faster.

If my memory serves me correct, most of the math done in DECB is floating point. There are 
a few routines that do use interger math. 

> How about some more ideas (and maybe some code)!

How about compacting the graphics commands in SECB so that you have say LINE and not 
both LINE and HLINE. and so forth and so forth. That could possibly cut out 4K or more of 
code space. 

Also assemble a SECB to take advantage of the 6309 instruction set. Not sure how much 
that would shrink the code but it possibly could improve the speed a bit. 

Dang if the MC9S12(X) series only had a U register, porting to that processor would even be 
a neat project. A COCO3 with a bus speed up to 40 MHz and a CPU clock at upwards to 
80MHz would be neat to see. I like the PLL in the HC12 line. 

Give me enough time and i might come up with some more ideas


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