Re: Why not just reproduce the second sight card?

[PZ <skierpaul@yahoo.com>]

I know that they used to make Line Memory that was perfect for this
application as well.  Don't know of any RAM's that do this currently,
but I'm sure they exist in some form or another.

- Paul

On Apr 20, 4:05 pm, Alex Freed <alex_n...@mirrow.com> wrote:
> Michael J. Mahon wrote:
>
> > The problem is that attractive conversion of IIgs RGB to VGA depends
> > on characteristics of the converter that are not usually specified,
> > and so are hit-or-miss unless someone actually tries one and finds
> > that it works well.
>
> > The reason for the problem is exactly the same as the one that Alex
> > Freed addressed in his recent mod to the //e VGA adapter for Carte
> > Blanche--the need to resample Apple video at a non-optimal rate.
>
> It is not terribly hard to convert GS video to something that a VGA
> monitor will like with even a smallest FPGA like a $7 50AN from Xilinx.
> Especially if you can treat R, G and B as digital signals to avoid A/D
> conversion. Just capture a single scan line at 14.xx MHz and send the
> same data twice to VGA sampled at 25 MHz. Two VGA lines last exactly as
> long as a single NTSC line. Internal dual-ported RAM inside the FPGA is
> perfect for the job.
>
> -Alex.