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Re: What GSE-Reactive Really Needs to Make
PZ wrote:
The problem with scan doubling is that you decrease the overall
resolution of the frame - you take the first half of an NTSC frame and
double it, then the second half and double it. Each half is 1/2 of the
full resolution.
Not quite sure what you're getting at here...
Scan doublers store a whole NTSC line, then play it back twice.
There is no loss of resolution, just a replication of data to
get more scan lines.
The problem with deinterlacing is that that you generate blur artifacts
when things are in motion since the second half of an interlaced frame
occurs AFTER the first (in time). When you combine the two halves into
one frame the time distortion occurs in the onscreen image.
But no (ordinary) Apple II produces interlaced video. Of course, if
someone has animation that runs at 60 fps (!), then successive fields
would be different.
I'd be happy just to get a stable, easy to look at text display. ;-)
The only real workable way to get quality video is to bus snoop and
recreate the video from scratch. If you're going to do that, might as
well go straight to DVI or HMDI.
No, it can be done by correctly sampling the Apple II video--but so
far no one seems to do that. ;-( The sampling clock must phase lock
to the Apple dot clock, preferably at an integer multiple (even 1x is
OK). There is plenty of dot clock signal to lock to, but most existing
(inexpensive) scan doublers don't lock to 14MHz--at least in monochrome.
Snooping the frame buffer is a fine way to go if you can get into
the Apple to do it.
-michael
Music synthesis for 8-bit Apple II's!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
tool--and it is seriously underused."