[Coco] Detecting CoCo 1 versus CoCo 2

[farna at amc-mag.com]

Date: Wed, 16 Oct 2024 23:43:37 -0500
 From: RETRO Innovations <go4retro at go4retro.com>

So, when I boot a CoCoSDC and it says "CC2" in my CC2, it's because the
CC2 has the extended BASIC ROM?
---------------------------

Possibly, but the CoCo1 could be upgraded to Extended Color BASIC, and 
the first 16K CoCo2 didn't have ECB (26-3026 models). For all practical 
purposes a CoCo1 with ECB is functionally the same as a CoCo2 with ECB, 
as pointed out. The slight differences don't usually matter UNLESS there 
was some unusual feature a programmer used.

Your reference to a "special semi-graphics mode" inspired a search 
though. I think I found something you can use to determine if it's a 
CoCo2 (therefore has to be a 1, or maybe a 3... a memory check will 
differentiate those). There was a special semi-graphics mode 8 in the 
CoCo2 VDG. See this: 
https://forums.atariage.com/topic/288322-hlo-projects-color-computer-2-semi-graphics-mode-8/
This is a function of the 6847 VDG, so a later model VDG in a CoCo1 (pin 
compatible!) would show Mode 8 also. So I don't think this will help 
much either at this point.


-- 
Frank Swygert
Fix-It-Frank Handyman Services
E-mail: farna at att.net
Phone: 803-604-6548