Re: video card for IIGS

[a_specto@alcor.concordia.ca (Mitchell Spector)]

"binaryside" <binaryside@yahoo.fr> wrote:

>Please, where can I find a video card for my IIGS which could offer a better
>resolution  than the original one?

    There were two such video cards, unfortunately both have been out 
of production for a number of years and now considered quite rare.

    The Second Sight is obviously one. As it uses a more or less standard
VGA chipset (the Oak-087) it's technically capable of producing a wide  
range of resolutions and color depths, though the IIgs will _not_ ordinarily
take advantage of them. Most native Apple II video modes are emulated 
by the card and shadowed onto a fixed 640x400 signal at 70 Hz refresh. 
Video remains the same number of pixels and colors per screen as before,
though with the advantage of being able to display on a VGA-compatible
display (albeit less attractive looking in some respects, due to differences
between NTSC-RGB and VGA). I don't believe it would work with modern
LCD displays as those operate on fixed resolutions, unlike CRTs. At the
very least it would have to stretch image to the point of heavily distorting
it, assuming it could be done.

    It is possible to display higher resolutions and color with the Second
Sight but you must have software that specifically supports it. As that
stands this consists of about a half-dozen graphic viewers for GIF, TIFF,
JPEG, etc. From memory, these only supported a maximum of 640x480
in 15-bit color. Essentially the card is useful for connecting the IIgs up
to a modern CRT (and quite possibly an LCD overhead projector; yet
again I'd question the feasibility of flat panel LCD displays).

    The other, which few people think of as a video card, is the Apple II
Video Overlay Card. Its main function is as a genlock device, but it
does duplicate the IIgs's built-in video and capable of driving a CRT
display independently. It supports interlaced video and can be used
to display 320x400 and 640x400 video on, say, an AppleColor RGB 
display--unlike the IIgs. SuperConvert is one program that lets you 
take advantage of this to display converted graphic images at higher
vertical resolutions.

    Incidentally, there just happens to be Second Sight for auction on 
eBay at the moment. Expect it to fetch a few hundred dollars though. 
I have both a Second Sight and Video Overlay Card in my IIgs sitting
beside me, though I'm not likely to part with either.

Mitchell Spector
a_specot@alcor.concordia.ca