[Coco] CoCo 128-column text mode

[Nick Marentes]

On 8/01/2015 5:34 AM, Mark Schoenberger via Coco wrote:
> I have heard of this mode.  Only 80 characters across are visible.but it scrolls.  It is a documented mode in the GIME.
>
> OS-9 does support this mode and I have tried it out.  Been a long time since I played with it, though.
>
>

It is simply the virtual hardware enable register (HVEN at $FF9F) used 
many times in games. It works for both graphics and text mode.

Nick