[Coco] MC6847 VGA (FPGA) Project underway...

[Torsrten Dittel]

Brendan Donahe <brendan at ...> writes:

> Very interesting information.  I'll have to add "Flee!" to the test suite
> for when we get to the Dragon.
> 
> Dragonfire does work with CoCoVGA on the CoCo 2 today, so I must have the
> data/CSS latching pretty close, at least.

> > [...]  I think the only time I've seen this used in anger is in
> > the PAL hack of DragonFire, and even then only used to change the border
> > colour for the bouncing message.

Brendan,

I assume Ciaran is referring to

http://www.roust-it.dk/coco/DRAGFIR2.BIN

Though, not to the ROM Pak game itself (I patched this some 30 years ago to
display the "mixed" PMODE3 SCREENs correctly on PAL 50Hz machines) but
rather to a little intro I squeezed into some free bytes between the
actually ROM dump and the loader which copies the ROM binary to the upper
32K in all-RAM mode. This is showing some more wierd mode mixing (even on
the border) and smooth horizontal and vertical scrolling under my teenage
hacker nick name DEPPELVISION.

As far as I know, Ciaran's XROAR is the only emulator in town being able to
display this correctly like on a 50Hz PAL CoCo2B (6847T1) with 64KB.

I would see this (the weird intro) as the extreme end of benchmark programs
and for your project it should be nothing more than the icing on the cake, I
wouldn't spend too much time on it in the first version. However, it would
be nice to see your VDG replacement working correctly on a 50Hz PAL machine
and then i.e. display the patched Dragonfire II correctly.

Regards,
Torsten