[Coco] (Probably stupid and newbie-ish) CoCo hardware question

[Juan Castro]

On Wed, Jun 27, 2012 at 10:35 AM, John E. Malmberg <wb8tyw at qsl.net> wrote:

> On 6/26/2012 1:42 PM, Arthur Flexser wrote:
>
>> Frank, that's the first time I've heard that explanation for why the
>> CoCo 3 runs in all-RAM mode.  (That Tandy had rights to use, but not
>> modify, the Microsoft ROMs.)  It seems very plausible to me.  Do you
>> know this for a fact, or is it just a reasonable conjecture?
>>
>
> I always assumed that it was done because that was the easiest way to
> extend BASIC beyond the DISK BASIC ROM.
>
> Both the BASIC and EXTENDED BASIC ROMs use a "patch" table in RAM that
> allows them to be extended.
>

Well, yeah, but that's limited. I do just that in
CaChars<http://sourceforge.net/projects/cachars>,
but there's things I can't do without ROM patching. (Like making
PRINT at work properly, for instance.)

That same patch table allows ROM Extended Color Disk Basic to run in ROM
> under the FLEX-09 using the FLEX-09 keyboard and screen I/O on a Color
> Computer I/II.
>

Believe it or not, I am becoming aware of this Flex-09 thing at this very
moment. Gotta do some research... oh, yeah!
http://www.flexusergroup.com/flexusergroup/default.htm

Juan