[Coco] Color BASIC 1.1 / memory detection

[jon bird]

Hi,

I have just recently resurrected my old Coco 1 (it's a 26-3004A variant) 
and have been putting it back to an original (working) state (I had been 
plugging various additional cards & even a Dragon ROM into it at some 
point).

The info I can find on this version of the CoCo was that it was shipped 
with 16K RAM, Color BASIC. It had an Extended BASIC 1.1 ROM fitted many 
years ago and as part of my various "upgrades", replaced the 16K RAM 
chips with 4164 DRAMs & also switched over the jumpers.

What I am finding though is that having restored the original Color 
BASIC 1.1 ROM, it is only reporting a 16K memory fit. I'm pretty sure 
that when I had the Dragon ROM fitted, it could access the full 32K (and 
I'm also fairly sure I had OS9 running on it as well which suggests the 
full 64K is accessible). So this seems to be a feature of the BASIC ROM.

I did come across this article from the archive:

http://coco.maltedmedia.narkive.com/2DM5LvJ2/color-basic-1-0-1-2-differen
ces

which backs up some other information I found that the original 1.0 ROM 
did not support >16K memory fit but that the 1.1 ROMs do.

Can anyone shed some light on this behaviour?

Cheers,


Jon.

-- 
== jon bird - software engineer
== <reply to address _may_ be invalid, real mail below>
== <reduce rsi, stop using the shift key>
== posted as: news 'at' onastick 'dot' clara.co.uk