[Coco] again: CoCo RGB to VGA conversion

[Nickolas Marentes]

Has anyone seen what a CoCo looks like on a VGA display?

Try displaying something that represents 620x200 resolution on a PC. What
the PC video output does is to scanline double vertically to convert the
signal to VGA resolution. Try running some old DOS games designed for CGA
resolution on your PC's VGA monitor.

It looks awful! It's so blocky, I'll stick with a correctly matched 15Khz
analogue monitor like the CM8 or better still, an Amiga RGB monitor.

Unless the CoCo can generate a proper 640x400 resolution image (not just
scan doubled), you will actually be downgrading your video output.

On the other hand, if the CoCo can be made to generate a blank scanline
between every real scanline, this will work correctly.

Personally, I think a VGA adaptor that buffers the first frame of full CoCo
video and then outputs a second frame interlaced with the first will give
nice high res (640x400) but I think this would only be suitable for display
of static images or slow update screens.

Nick