[Coco] video modes for diagnostic cart

[Allen Huffman]

> On Nov 29, 2025, at 8:57 AM, Alex Evans via Coco <coco at maltedmedia.com> wrote:
> 
> I have gotten to the point where I am currently working on the video test
> for my diagnostic cart.  For video tests I have covered all (13) of the
> coco1/2 video modes and for the CoCo 3 code to test the ones that are
> implemented in the GIME. This kind of complete coverage for the GIME seems
> unreasonable. I see two options: 1) implement a reasonable subset of the
> GIME modes in the test (which ones?) or have a GIME subtest that allows the
> user to play around with the parameters to see the results. Which do you
> all think would be better?

Well, I hate to be “that guy” suggesting things and not being able to do the work, but…

…having a test for “all known” GIME modes would be useful for folks working on emulators. Not sure how that would be approached, but things like the scroll offset register stuff, and things like the “64/128 column” screens and such are a mystery except for a handful of programs that used them. Stuff like that seems to break emulators early on. A way to test could be useful for FPGA, emulation, etc.

	— A