Hi;

Thanx to all who read and replied to my question (PC/AV).

To recap, ATI All in Wonder 7500 running into a Mits. 35MX1 (not sure if it's a
CS or a CK). It appears, as said that the signal is not quite standard. The
COMB filter in the Mits. really doesn't get along well with this signal. It
does do a decent job on regular TV broadcasts though, and it has been rebuilt
(which means replacing just about every SMD lytic on it).

Now I built this system for the guy and when it was here I connected it to my
Sony KPR 36XBR which has the old analog one line COMB filter (which has been
aligned to a T on a standard NTSC signal). It separated the Y and C just fine,
but being a one liner, it had the "hanging dots" on the first line of a block
of highly saturated color. The interesting part is that the hanging dots are
stationary ! Normally they move due to interlace. Now the signal udoes/u
have frame/field interlace. I can tell on the screen, just like a normal signal
the raster lines can appear to move up or down if you let your eyes follow. Now
in the ATI video however, either the H and V frequencies are shifted slightly
or the color subcarrier is, proven by the fact that the hanging dots do not
move. The fact that the COMB filter is not behaving well leads me to believe
that it is the color subcarrier that is shifted, but this might not be true,
the Mits COMB filter might use sweep timing to generate a clock signal, but it
doesn't matter, either way the phasing is off and it looks terrible. Don't
forget it is just fine on regular video.

Iv'e read in the past about sets that bypass the COMB filter for a VCR, and
indeed from a VCR a COMB filter only degrades the quality. How would a set know
it's a VCR rather than a video game or a component or satellite tuner ? I guess
it could be detected due to the time base errors inherent in a VHS signal, but
I haven't seen it implemented on any schematic that I know of, but it could be
buried in logic where I would never see it.

This all could become a moot point, (but interesting) if only I could get the
Mits to use the SVHS input. Now that Iv'e read the replies (thanx again) I
wonder if the little microswitch might just be dirty and if I plugged and
unplugged the input about 50 times it might just start working. The question
now is, is the switch at the SVHS or composite jack ? I used one of the audio
cables for the composite and can confirm that the TV is using the composite
even when the SVHS plug is inserted. This (input 1) composite has been used in
the past but to my knowledge the SVHS input has thusfar never been used.

Jumping to another reply suggesting I look in the display properties on the PC,
I looked around there and there are very few options, for one the refresh is
going to stay 60 Hz no matter what for the TV. Certain other refresh rates for
the PC monitor cause loss of the TV display. Apparently there are some
"illegal" combinations that simply won't work when you have the desktop (not
extended) on the TV. There is one thing I might try though, I did notice a
setting for 8 bit or 16 bit color. Of couse it gives me all the way to 32 bit
for the PC monitor but not the TVO. At 8 bit, my TV looked pretty good, just
how much possibility is there that the more advanced COMB filter might benefit
from the 16 bit setting? I think that would depend on if the timing is changed.
Perhaps the 8 bit setting is for gamers who would want to devote the most
resources and VRAM to the game.

I'm not particularly crazy about ATI's software. I think it goes a bit too deep
into the firmware, this evidenced by the fact that if you set a bad combination
of settings you lose the BIOS screen etc. when booting, not just the Windows
driven display. Damn video card BIOS ought to be a little more stable than
that. This card had the same type of problems in an Athlon XP system, and I
engineered the sale of it to this guy because I was told that the ATI cards
work better with Intel. Building a P4 system it seemed a good way to go. (nice
price too)

I have downloaded and tried to install ATI's update/patch/whatever file twice
and there is an error in the software. It won't run.

Anyway, thank you all for even reading these long posts. I don't mean to be
long-winded but these problems can be complex, and I like to include detail
like what has been tried etc. The stuff about the COMB filter not working right
is more esoteric, on the practical side I see I'll have to find out why the
Mits. doesn't switch to the SVHS input. I'm on it. (of course the Mits. is now
sitting on a 4 foot high shelf with 3 VCRs and a DVD on top, but I'll manage)

This isn't the end of my concerns though, I wonder how this signal will record
on a VCR. The CNR in the VHS system is pretty COMB dependant. I'll let you know
how that turns out next time I go there.

Next time I think I'll get the GeForce .

JURB