[Coco] Suggested RAM area for ML program to be used from BASIC?

Gene Heskett gene.heskett at verizon.net
Sat Jun 7 18:22:24 EDT 2008

On Saturday 07 June 2008, Fedor Steeman wrote:
>Hi everyone,
>What is the best area in memory to place a ML program that complements and
>can be used from BASIC? And this should go for CoCo 1/2 & 3!
There is no one best address for that that does not steal memory from rsbasic.

There was a very handy little edit assistant that Jake Commander wrote back in 
the old grey ghost days called Chrmakey I think.  His original code borrowed 
the keyboard scan address somehow that I've forgotten now, and when the white 
coco1's came out with basic1.1, I had to patch it and discovered that Jake had 
used a direct jump in the original that was supposed to be an indirect [jump] 
according to the RS published guidelines.  But, this lived at an address just 
below the $8000 in basic space, and basic didn't know about it which lead to 
some interesting crashes with big basic programs, so while I was doing the 
patch, I wrote a little thing that put the coco1 & 2's in the all ram mode, 
then copied this utility to the top of ram above the disk controller and 
extended basic, so it started at $E000. I ran it that way until the coco3's 
came out and the patches to the basic roms in the coco3 sadly used nearly all 
that memory.

And it was such a handy little utility too, comparable to bottled beer and 
sliced bread in all around usefulness.  That was also my first experience with 
machine code, and I have to thank Jake profusely for being the teacher that he 
was.  Without him being aware of it, he was a heck of a teacher.  Sadly he 
disappeared from the coco scene, and 20 years ago Stan Viet in the Computer 
Shopper was also looking for him, but never wrote that he had been found that I 
saw in print.

The lesson I learned was that there really isn't anyplace to hide such utilities 
that someone else won't find and use in the future.  I'd already been doing 95% 
of my work in os9 level 1 version 2 by then & that just flipped the switch so 
that it was a race when I turned it on to get dos typed in before the monitor 
was warmed up enough to see it.  Now, with hdb-dos in my TC^3 controller, I 
have to type an 'F' key during a 15 second cold boot countdown, to have it run 
rsbasic, the default is nitros9 from the hard drive, now a 1GB seagate scsi on 
a tc^3 controller.

Over the years there has been an ST-238 (30 megs) on a B&B controller, then a 
Disto SC-II with a 4n1 came to live here and a Maxtor 7210s (128 megs) on it 
ran till I had to slap it around to get it started, so now its the first 500 
meg partition of a 1GB that I use, the second 500 is used for 255 virtual 
floppies with hdb-dos.  I only use rsbasic for hardware troubleshooting now.

To summarize, the original coco, coco1, (both assuming a full 64k of memory in 
them) & the coco2 can be put in the all ram mode and small utilities hidden at 
$E000 to $FEFF, but the coco3 has very little similar leftover space.


Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
The reward for working hard is more hard work.

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