[Coco] more overscan antics on the coco II

[Torsten Dittel]

Simon Jonassen <simon at ...> writes:

> Even more twiddling about reveals more posibilities....
> 
> http://roust-it.dk/coco/more_overscan.jpg

Simon, interesting. Did you figure it out on a real CoCo2 system, or is it
just XROAR showing that behaviour? I assume it's a "stable" display you're
showing? Could yo achieve that as well in HiRes Graphics modes?

Did you have a look at http://TRS-80.CC/DRAGFIR2.BIN ? This has some stable
partial border lines painted, some of them even with smooth vertical
animation. Works with XROAR and on 50HZ PAL machines only.

A screenshot here:

http://www.6809.org.uk/tmp/da/pal_coco_probe/pal-dragonfire-1.png

Keep researching! I guess the VDG contains more funny things we don't know
yet (e.g. I never played around with desyncing it using the Hispeed POKE
65497,0 at the right point of time and then POKEing back to slow speed in
the visible area).

Regards, Torsten