[Coco] Color BASIC program on a cartridge?

[Dave Philipsen]

I made a cartridge a long time ago for the CoCo 3 (around 1989) that 
used a nice metal Disto housing.  I sold a few dozen for a commercial 
endeavor along with the CoCo 3 (which at the time was available for 
$99).  The cartridge had a socket for a '256 EPROM along with an 8-bit 
latch and an octal buffer which interfaced to a matrix numeric keypad.  
(The board design was hand-taped and had a nice gold-edge connector!) 
The program was written in SECB (BASIC). I've got the source code for 
the loader floating around somewhere but all you have to know is where 
the BASIC program starts and ends and where BASIC saves the pointers to 
these locations.  You can do a CSAVEM or SAVEM to save the binary image 
of the tokenized BASIC program, make a notation of the pointers, and 
copy that image to EPROM along with the loader program.

The loader program looked like a disk controller EPROM with the 'DK' 
signature at the beginning which allowed the loader to auto-start. With 
an 'ON BRK GOTO' in your program you can keep people from accidentally 
or intentionally stopping the program.

I imagine John's program does pretty much the same thing but if you get 
in a bind or have problems or want to try an alternative program let me 
know.  I can dig up the code.

Dave


On 8/7/2017 10:05 AM, David Ladd wrote:
> John,
>
> Thank you for letting us know.  This will be very useful. :D
>
> It should be possible to put your basic program & any ML sub routines into
> the ROM space yes?
>
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> | David Ladd a.k.a. PacoOtaktay a.k.a. Drencor                          |
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> | Do you have your CoCo 3 yet?                                          |
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>
>
> On Mon, Aug 7, 2017 at 9:51 AM, John W. Linville <linville at tuxdriver.com>
> wrote:
>
>> One of the objections some people have had to distributing their
>> programs in cartridge form has been that their programs were written
>> in BASIC. With the help of some ancient knowledge from the Internet
>> (aka an old Geocities page from "PaulD"), some more recent advice
>> from Robert Gault, and my own experimentation, I have documented on
>> the Retro Tinker blog a means of loading Color BASIC (and Extended
>> Color BASIC) programs from a ROM cartridge:
>>
>> http://retrotinker.blogspot.com/2017/08/color-basic-
>> program-on-cartridge.html
>>
>> The technique (including the Errata changes described in the comments)
>> seems to be working for me. Elsewhere Barry Nelson pointed-out that
>> the technique doesn't work with CoCo3 "Super Extended Color BASIC"
>> programs. I did a bit more experimentation and I think I have that
>> working as well -- but that will have to wait for the next blog
>> post... ;-)
>>
>> Enjoy!
>>
>> John
>> --
>> John W. Linville                Someday the world will need a hero, and you
>> linville at tuxdriver.com                  might be all we have.  Be ready.
>>
>> --
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