Re: Alternatives to an applecolor RGB?

[Steve <srkh28@gmail.com>]

Hi Charlie,

Drew sent me an email mentioning what you had done - great stuff! Bill
has some 24bit plug on video boards to suit carte blanche. They havent
been allocated yet, but if you would like one to keep on keeping on,
then im sure he'd be happy to send you one. It seems the perfect add
on for your IIgs controller. The card is in the form of a plug on
board with a 24bit DAC and an apple mini VGA connector. The card comes
with an adaptor to normal15pin VGA. Its the same as the one alex has.
These are free to CB owners (until run out, plus postage etc)

http://alexfreed.com/FPGApple/FPGA_card.html  (its the one at the
bottom of the page)

Steve


On Oct 7, 7:58 am, Charlie <charlieD...@verEYEzon.net> wrote:
> On 10/7/2011 5:04 AM, Daniel Kruszyna wrote:
>
>
>
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> > Charlie<charlieD...@vereyezon.net>  wrote:
> >>> The problem is that any device that proposes to generate VGA video from an
> >>> Apple II (of any stripe) must also faithfully (instantaneously) render the
> >>> results of rapid video mode switching--a very difficult feat for non-native
> >>> video generation.
>
> >> I'm not sure I see the problem.  To switch video modes you need only "watch"
> >> for accesses to the appropriate soft-switches.  When a soft-switch is
> >> accessed the card switches to the appropriate circuitry, probably faster than
> >> the Apple II.  While "playing around" with the Carte Blanche VGA video I
> >> often have two monitors (one with the native Apple video and the other from
> >> the Carte Blanche) side by side and I see no perceptible difference when
> >> video modes are switched.  The hardest part (for the designer) is knowing
> >> what happens when certain soft-switch combinations are accessed.  The
> >> documentation is a little vague on some modes.
>
> > The difficulty arises when soft switches and video ram are changed _while the
> > screen is being drawn_. In this case, the converter must be synchronized to the
> > native video scanner.
>
> In the case of the Carte Blanche card the video RAM and soft-switches
> are being used in a very similar way to the native Apple.  Any problem
> that would arise from changes to the video RAM/soft-switches while the
> screen is being drawn should be the same for both.  The Carte Blanche
> and presumably the Second Sight card do not generate the VGA "on the
> fly" but buffer the video RAM and internally mimic the status of the
> soft-switches.  The speed of the card is much faster than the Apple so
> it can easily keep the buffer "up to date".
> As Alex has pointed out, the GS specific modes are not supported "out of
> the box".  Still with limitations (mostly with the number of colors) you
> can have a very sharp (some would say too sharp :-) Finder Desktop.  See
> the picture at this link:
>
> http://noboot.com/charlie/cbnotesgs1.htm
>
> Charlie- Hide quoted text -
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> - Show quoted text -