Re: 2 questions

[spec@vax2.concordia.ca (Mitchell Spector)]

In article jbcole@ix.netcom.com writes...

>what exactly does the video overlay card do?

    It's a genlock device (slot card) that Apple Computer sold for
use with the Apple IIgs and IIe.  As the name implies, it allows you
to overlay video signals, mixing the two so one is on top of the other.
Your probably familar with this technique from watching TV broadcasts,
often computer generated graphic logos, names, titles and animations
are superimposed over live video images. The VOC can have them appear
as solid opaque images or as translucent (a stained-glass effect).

    Another neat effect is the ability to input a video signal onto
your AppleColor RGB monitor. You can watch TV (full-screen) on the 
GS screen, or even have a live TV broadcast as your desktop background 
in the Finder.

>Can I use a IIgs monitor on a IIc?

    It would require a special analog-RGB adapter. Apparently there
was one made, although I've only heard about it through a reader on
comp.sys.apple2. The Apple IIc (and IIc+) has a Video-Expansion
port, with adapters you can generate digital/analog RGB or NTSC.
The only thing it works with directly would be special LCD displays, 
but these mostly likely have conversion circuitry built-in. One of
these days I need to repair my C-Vue LCD so I can try it out... ;)

Mitchell Spector
spec@vax2.concordia.ca