old computer to old tv, watching video, best way?

My neighbor has a very old Mitsubishi HD1080 TV with RCA and S-video
jacks, and a very old HP laptop with VGA and USB jacks. If she gets a
VGA to S-video converter cable will that carry the video signal to the
TV so she can watch movies on the TV? (she already has external speakers
so no audio is needed). She's looking for the least expensive solution.
I found this cable just searching around, do I need a converter box or
will this work?

VGA to TV RCA S-video Converter Adapter Cable PC Laptop
https://www.amazon.com/S-video-Conve.../dp/B000P3UB24

Thanks,
Mike

Mike S wrote:
My neighbor has a very old Mitsubishi HD1080 TV with RCA and S-video
jacks, and a very old HP laptop with VGA and USB jacks. If she gets a
VGA to S-video converter cable will that carry the video signal to the
TV so she can watch movies on the TV? (she already has external speakers
so no audio is needed). She's looking for the least expensive solution.
I found this cable just searching around, do I need a converter box or
will this work?

VGA to TV RCA S-video Converter Adapter Cable PC Laptop
https://www.amazon.com/S-video-Conve.../dp/B000P3UB24

Thanks,
Mike

Start with a scan converter.

https://www.newegg.com/Product/Produ...9SIA4SR1WR1851

What those do, is they convert progressive 1024x768, to 525 line
interleaved NTSC. The device probably contains a frame buffer, and
reads out the stored frame in interleaved order.

In the process of doing so, thin horizontal lines can "disappear"
on the output. This is solved by the hardware doing convolution.
The scan converter looks at multiple horizontal lines (three lines,
five lines or seven lines), and makes features in the output "thicker".
This helps (marginally) with things like PowerPoint slides.

Now, when you get to the S-video or Composite end of things,
there is a second problem. Some TV sets have poor DC restoration
properties. The picture will look horrible. I have two tiny
CRT TV sets here, where this is a problem.

To fix that, take the video from the scan converter, and run
it into a Channel 3 modulator. Then run a coax from the output,
to the TV set. This assumes the TV set still has an NTSC tuner
and can tune to channel 3. I'm not aware of any modulators
that take S-video or composite and do DTV for you.

http://www.bestbuy.com/site/insignia...?skuId=4947028

I use an older RadioShack brand RF modulator, to connect a $50 DVD
player, to one of the TV sets, and the picture looks great (compared
to coming in on Composite). Obviously, the res. is SD, and can
never look better than the hardware path allows. And that's where
my RF modulator sits today. There are no more NTSC broadcasts here,
so there is nothing to interfere with channel 3 particularly. The
only thing similar is ATSC 8VSB, and that starts at slightly higher
channels. The idiots put some of our ATSC on VHF, but not down at
channel 3 fortunately. There aren't enough broadcasters left in the
country, to need more than UHF for them. Even half of the UHF band
would be enough.

*******

The old-style VGA to Composite passive cables were a scam. They
relied on the sense pin standard, declaring that the output was
composite, and require a computer that will output such a signal.
That stopped like... a thousand years ago. I tried to find a
schematic for one, and this is all I could find. It looks like
it might be an attempt to mix a Luminance and Chrominance signal
together, but I can't really be sure what that's supposed to do.
Unless the GPU supports the necessary mode, the correct format
of signals will never appear on the VGA connector. That's why
those scam cables all end up in the landfill. I don't think
I've ever run into a "success story", to be able to tell you
what computer started this nonsense.

http://geoffg.net/Images/Maximite/Composite%20Video.png

I think I have something here, that will output a TV like
signal - it might even be monochrome as far as I can remember.
And the clever GPU in that case could produce interleaved
without a problem. And it relied on a sense pin thing as well.
I have a "dongle" here, with sense switches on it, for commanding
a particular mode. The computer probably hasn't been powered
up in at least 15 years. I cannot remember any more details
than that. And it would not be compatible with that VGA
scam cable, either... That was an output mode on some
old Macs.

*******

Unless that TV set has some other connectors on the back,
there is no "best way" to get there. This is a project
for someone who likes to tinker, not a "consumer of media"
quality project. Even if the set had YPbPr on the back,
you'd have more options to get there. Composite and S-video
are the suckiest interconnect types ever invented, and
sadly, all too common.

Paul

On 2/25/2017 9:12 PM, Paul wrote:
Mike S wrote:
My neighbor has a very old Mitsubishi HD1080 TV with RCA and S-video
jacks, and a very old HP laptop with VGA and USB jacks. If she gets a
VGA to S-video converter cable will that carry the video signal to the
TV so she can watch movies on the TV? (she already has external
speakers so no audio is needed). She's looking for the least expensive
solution. I found this cable just searching around, do I need a
converter box or will this work?

VGA to TV RCA S-video Converter Adapter Cable PC Laptop
https://www.amazon.com/S-video-Conve.../dp/B000P3UB24


Thanks,
Mike

Start with a scan converter.

https://www.newegg.com/Product/Produ...9SIA4SR1WR1851

What those do, is they convert progressive 1024x768, to 525 line
interleaved NTSC. The device probably contains a frame buffer, and
reads out the stored frame in interleaved order.

In the process of doing so, thin horizontal lines can "disappear"
on the output. This is solved by the hardware doing convolution.
The scan converter looks at multiple horizontal lines (three lines,
five lines or seven lines), and makes features in the output "thicker".
This helps (marginally) with things like PowerPoint slides.

Now, when you get to the S-video or Composite end of things,
there is a second problem. Some TV sets have poor DC restoration
properties. The picture will look horrible. I have two tiny
CRT TV sets here, where this is a problem.

To fix that, take the video from the scan converter, and run
it into a Channel 3 modulator. Then run a coax from the output,
to the TV set. This assumes the TV set still has an NTSC tuner
and can tune to channel 3. I'm not aware of any modulators
that take S-video or composite and do DTV for you.

http://www.bestbuy.com/site/insignia...?skuId=4947028


I use an older RadioShack brand RF modulator, to connect a $50 DVD
player, to one of the TV sets, and the picture looks great (compared
to coming in on Composite). Obviously, the res. is SD, and can
never look better than the hardware path allows. And that's where
my RF modulator sits today. There are no more NTSC broadcasts here,
so there is nothing to interfere with channel 3 particularly. The
only thing similar is ATSC 8VSB, and that starts at slightly higher
channels. The idiots put some of our ATSC on VHF, but not down at
channel 3 fortunately. There aren't enough broadcasters left in the
country, to need more than UHF for them. Even half of the UHF band
would be enough.

*******

The old-style VGA to Composite passive cables were a scam. They
relied on the sense pin standard, declaring that the output was
composite, and require a computer that will output such a signal.
That stopped like... a thousand years ago. I tried to find a
schematic for one, and this is all I could find. It looks like
it might be an attempt to mix a Luminance and Chrominance signal
together, but I can't really be sure what that's supposed to do.
Unless the GPU supports the necessary mode, the correct format
of signals will never appear on the VGA connector. That's why
those scam cables all end up in the landfill. I don't think
I've ever run into a "success story", to be able to tell you
what computer started this nonsense.

http://geoffg.net/Images/Maximite/Composite%20Video.png

I think I have something here, that will output a TV like
signal - it might even be monochrome as far as I can remember.
And the clever GPU in that case could produce interleaved
without a problem. And it relied on a sense pin thing as well.
I have a "dongle" here, with sense switches on it, for commanding
a particular mode. The computer probably hasn't been powered
up in at least 15 years. I cannot remember any more details
than that. And it would not be compatible with that VGA
scam cable, either... That was an output mode on some
old Macs.

*******

Unless that TV set has some other connectors on the back,
there is no "best way" to get there. This is a project
for someone who likes to tinker, not a "consumer of media"
quality project. Even if the set had YPbPr on the back,
you'd have more options to get there. Composite and S-video
are the suckiest interconnect types ever invented, and
sadly, all too common.

Paul

Thanks for the very detailed reply Paul. I appreciate it. Unfortunately
the woman can't afford this stuff.

Mike S wrote:


Thanks for the very detailed reply Paul. I appreciate it. Unfortunately
the woman can't afford this stuff.

Well, I am a champion of buying TV sets with the
wrong connectors on the back, so I can only sympathize
with this situation :-)

Paul