[Coco] Wordpak RS update

[Chuck Youse]

Ok, folks, a few weeks ago there was some back and forth about the
various Wordpak models and some doubts about the 6845 CRTC in the middle
of all that business... 

I cracked open my Wordpak RS today - the registers are located at
$FF76-$FF79, and, as I suspected from the published schematics, it is a
6545, NOT a 6845.  And yes, the difference is vitally important to the
design..

I verified this, too, by swapping in a 68B45.  When the video registers
are jimmied, a valid display (and text) is generated, but no updates of
video RAM can take place because the 6845 lacks that one feature of the
6545!

C.