Re: VGA / SVGA Card / Adaptor for the ][+?

["Bryan Parkoff" <bryan.nospam.parkoff@nospam.com>]

    You can use VGA Box.  Just connects a cable from Apple II+'s NTSC video
port to VGA Box.  Connects from VGA Box to SVGA monitor.  No RGB is
necessary, but it will only display 40 column, low resolution and high
resolution.  I don't thnk that 80 column and double high resolution will
look nice on SVGA monitor because of limit frequency.

-- 
Bryan Parkoff
"Robert C." <robc638@startmail.ca> wrote in message
f86a396.0406141040.19a074c0@posting.google.com">news:f86a396.0406141040.19a074c0@posting.google.com...
> Is it possible to make a card or adaptor that will convert the
> composite video signal generated by the Apple to display on a VGA /
> SVGA monitor, maybe even increasing colour quality?
>
> I have been looking at a way of doing this, but I am stuck on how to
> decompose the video signal. One possibilty would be to tap directly
> into the Apple's portion of RAM where the video image is stored,
> taking into account the lo-res, hi-res and text areas, and switching
> the memory locations, and then convert this into RGB for output to the
> VGA monitor.
>
> Another approach would be to have the Apple "write" to a memory bank
> equivalent of the monitor, then "read" back this "memory map" through
> RGB to the SVG output.
>
> Sync-ing would be done using a PLL running as a multiplier of the
> Apple frequency to achieve the 72Hz required for VGA sync.
>
> Any ideas or suggestions?
>
> Thanks.