[Coco] Coco 2 6847T1 test program

Ciaran Anscomb cocomalt at 6809.org.uk
Thu Jul 20 03:23:56 EDT 2017

Ron Klein wrote:
> Somewhat related so for those who use MAME, there was a SG6 issue that is
> now being addressed by one of the MAME developers.

Is this where the value on the data bus is interpreted as font data?
With bit 6 inverting as usual, so bit 6 colour ends up fixed.

Used to good effect in the Dragon User published BASIC + M/C game Flee!
(exclamation mark in title).

Dragon 32 (original) and Dragon 64 ([m]) versions (not CoCo compatible)


To the original question: if it was to determine T1 presence
programatically, I don't think you can.  The VDG doesn't provide anything
you can explicitly read; there'd have to exist some slightly different
side-effect (e.g., hsync timing) for it to even be possible, and I really
doubt there are any.


More information about the Coco mailing list