Re: Apple II Video Overlay Card

[shack@pro-ict.cts.com (Randy Shackelford)]

ntt@apanix.apana.org.au (Jonathan Pratt) writes:

>> Also, does anyone know where one can be purchased, and at what price?

Catch as catch can nowadays

>The VOC requires a GS (slot 3) or an enhanced //e (any slot, but slot
>three is usually taken in the //e), and comes in a variety of forms. 

ROM 3 is said to be able to use the VOC in other slots but 3 only for ROM 01.
I use mine in my 01 //e upgrade instead of the ROM 3 on my desk. The card
doesn't use the slot's firmware space so slot 3 is ok on a //e.

>Their basic purpose in life is to allow the overlay of computer graphics
>onto an input video signal and produce a combined output (composite) video
>signal suitable for taping on any VCR (or equivalent).  The NTSC model
>accepts and outputs NTSC composite signals, while there are also PAL and
>SECAM models.  The VOC can ptoduce any of the GS video modes (even on the
>//e) and can even go one up by producing a 640 (320) * 400 mode.  The
>overlay function works by replacing one of the GS colours (one of the
>screen colours) with the video signal wherever it appears on the screen. 
>That is, if you were using a white on black text screen, and chose your
>'key colour' to be black, what you'd see on the monitor would be the video
>signal that you're sending in (from VCR or video camera) with all the text
>'overlayed' on top. (all the black would be replaced by the video signal
>but the white would remain and show up on top)  Of course you can get some
>excellent effects using different key colours with the graphics screens.

In addition to having a color completely replaced by video, you can set the
proportion of video to graphics for key and non-key colors. My favorite trick
is to connect the VCR video to the input then send the output to the monitor
or TV, then set both the key color and non-key colors to the same mix of
graphics/video. Usually I put each at half. The result is a translucent
display for what the IIgs is doing on top of the TV video. I run a headphone
cord from the VCR to the tube to get sound as well. Mighty cool.

>There isn't much software that I've seen that makes much use of the VOC
>other than a demonstration HyperStudio stack, and SuperConvert (this one
>uses the 640 * 400 mode, and can also let you use two monitors on the GS
>with different pictures on them).

Well this is a piece of hardware that works transparently with software. The
above is like saying there isn't much software that makes use of your
accelerator.

>In a fall (americanism) 92 StudioWare catalog, Roger Wagner Publishing
>were selling them new for $US419.95 (rrp = $US549.00) but I couldn't say
>what the current deal is.  At those prices, I dare say that RWP still has
>a few left over.  They can be contacted at:

Boy I'd get one if I could at that price. I got mine secondhand for $300 once
upon a time and thought I was doing well
--
Randy Shackelford                              "That's right, keep dancing
shack@pro-ict.cts.com                           on the minefield"
                                                                 -Al Bundy