[Coco] "Mini DOS" in early CoCo disk programs...

[Willard Goosey]

I'm not going to argue with Arthur, but another reason for the Kilgus
"DOS" is that the computer is the "TRS-80 Color Computer."  On the
Model 1,III,IV, the ROM you got with your disk controller wasn't patch
to BASIC to add disk I/O, it was a boot loader.  

On the Model 1 & III, the BASIC ROM is always there, and TRS-DOS can
call usefull subroutines in it.  The Tandy people may have been
planning for the CoCo to be the same way.

Another purpose for "Color TRS-DOS" may have been to help port Model
III programs to the CoCo.  Things like Scripsit, Profile,... I don't
know how those programs were developed for the CoCo.  Tandy may have
had a useable z80 to 6809 assembly source converter.  Even if just the
same people worked on both z80 and 6809 versions, they'd want the same
sort of OS routines that "real" TRS-DOS provides, because that's what
they were used to.

An EDTASM itself is Microsoft code, isn't it?  They may have insisted
on the machine providing certain OS routines.  In 1983 Microsoft
wasn't seriously into operating systems.

The problem with the plan, frankly, is that the CoCo has a 32K ROM
rather than a 16K ROM like a Model III.  That's a lot of memory space.
Then you load a DOS?  Fergit it.

Another problem is that AFAIK you couldn't freely distribute Kilgus's
DOS.  Hence, if you wrote a program that used it, that program was
only useful to people who already had the DOS somewhere.  

And there's the fact that it ignores its own rules and scribbles on
the text screen directly, which means that it doesn't display on the
CoCo 3 hi-rez text modes.  (Yes, I know EDTASM itself works fine on
the 80-column screen.)

The problem with the directory entries isn't just an emulator issue.
Some editors/word processors that do their own disk I/O also create
directory entries that BASIC is happy with but offends Kilgus's DOS.
I wrote a simple little BASIC program to zero out the offending bytes,
if anyone needs it.

It's a shame Kilgus's Color TRS-DOS was so limited.  Maybe if Logical
Systems had gotten their hands on it... Color LS-DOS!  I think I'm
being silly now.

Good night,  
Willard
-- 
Willard Goosey  goosey at sdc.org
Socorro, New Mexico, USA
"I've never been to Contempt!  Isn't that somewhere in New Mexico?"
   --- Yacko