IC - VGA to PAL

[fuzzymonkey]

Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal to
PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar and
googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks

 

[atec 77]

fuzzymonkey wrote:

Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal
to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar
and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks
check whats used in the video output on cctv dvr , should work and will

be cheap

 

[ian field]

"atec 77" <"atec 77"@hotmail.com> wrote in message
news:hkjuis$ie3$2@news.eternal-september.org...

fuzzymonkey wrote:
Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal to
PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar
and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks
check whats used in the video output on cctv dvr , should work and will be
cheap

If you only want the one, you could salvage a suitable chip from any
computer with a UHF/PAL output, like some of the Commodore models and maybe
Atari.

 

[David L. Jones]

fuzzymonkey wrote:

Hi,
I'm trying to to get my hands on a chip that will convert a VGA
signal to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim,
Jaycar and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

http://www.analog.com/en/digital-to-analog-converters/video-encoders/ad725/products/product.html

Dave.

--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.eevblog.com

 

[Ray]

"fuzzymonkey" <fuzzymonkey87@hotmail.com> wrote in
news:idKdnckf-_aI_vDWnZ2dnUVZ_sadnZ2d@westnet.com.au:

Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal
to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim,
Jaycar and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks

If you intend to drive a normal TV set, have you considered the scanning
frequencies?

The horizontal is roughly twice as fast as the conventional 15625Hz (64us)

You may well end up with two side by images with half the scan lines!

Ray

 

[fuzzymonkey]

Actually, that's exactly what happens now! The screen is a small LCD from a
PSone.
pic -
http://www.retroleum.co.uk/wp-content/uploads/2009/05/psonelcd_front.jpg

It can display NTSC or PAL and takes a composite or S-video connection. From
VGA i connected Red, Green, Blue, Ground and HSync to the screen. It shows a
very very blury double image; side by side. I figure it's because the screen
only accepts an interlaced signal and the card outputs a progressive scan
signal... but this is all still new to me so maybe i got it wrong.
If i use something like Dave mentioned
http://www.analog.com/en/digital-to-analog-converters/video-encoders/ad725/products/product.html I
think it would work for what i need.

Anthony

"Ray" <spam@spamal.com> wrote in message
news:Xns9D185FAA4A7D9zathranetpacenetau@216.151.153.43...

"fuzzymonkey" <fuzzymonkey87@hotmail.com> wrote in
news:idKdnckf-_aI_vDWnZ2dnUVZ_sadnZ2d@westnet.com.au:

Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal
to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim,
Jaycar and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks


If you intend to drive a normal TV set, have you considered the scanning
frequencies?

The horizontal is roughly twice as fast as the conventional 15625Hz (64us)

You may well end up with two side by images with half the scan lines!

Ray

 

[fuzzymonkey]

I have a Sega mega drive. The MB3514 IC is perfect.. except i don't have the
soldering skills to remove the chip without damaging it.

"ian field" <gangprobing.alien@ntlworld.com> wrote in message
news:zYhbn.227814$yt6.67285@newsfe14.ams2...

"atec 77" <"atec 77"@hotmail.com> wrote in message
news:hkjuis$ie3$2@news.eternal-september.org...
fuzzymonkey wrote:
Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal
to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar
and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks
check whats used in the video output on cctv dvr , should work and will
be cheap

If you only want the one, you could salvage a suitable chip from any
computer with a UHF/PAL output, like some of the Commodore models and
maybe Atari.

 

[fuzzymonkey]

Still a very cool idea. Thanks.

"ian field" <gangprobing.alien@ntlworld.com> wrote in message
news:zYhbn.227814$yt6.67285@newsfe14.ams2...

"atec 77" <"atec 77"@hotmail.com> wrote in message
news:hkjuis$ie3$2@news.eternal-september.org...
fuzzymonkey wrote:
Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal
to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar
and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks
check whats used in the video output on cctv dvr , should work and will
be cheap

If you only want the one, you could salvage a suitable chip from any
computer with a UHF/PAL output, like some of the Commodore models and
maybe Atari.

 

[fuzzymonkey]

Wow i just realised you're Dave from the eevblog! Pays to look at peoples
signatures. Love the video blog!

I was looking a similar chip on rsComponents. So the one you suggested is
great, only problem is the minimum purchase quantity from analog.com is 100!
I only need 1 (or 2 since i'll probably destroy the first one.)

"David L. Jones" <altzone@gmail.com> wrote in message
news:0Mlbn.6713$5n.6481@newsfe23.iad...

fuzzymonkey wrote:
Hi,
I'm trying to to get my hands on a chip that will convert a VGA
signal to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim,
Jaycar and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

http://www.analog.com/en/digital-to-analog-converters/video-encoders/ad725/products/product.html

Dave.

--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.eevblog.com

 

[David Eather]

fuzzymonkey wrote:

Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal
to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar
and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks

http://www.dealextreme.com/details.dx/sku.26804

$31USD

 

[Sylvia Else]

On 7/02/2010 11:58 AM, fuzzymonkey wrote:

Actually, that's exactly what happens now! The screen is a small LCD
from a PSone.
pic -
http://www.retroleum.co.uk/wp-content/uploads/2009/05/psonelcd_front.jpg

It can display NTSC or PAL and takes a composite or S-video connection.
From VGA i connected Red, Green, Blue, Ground and HSync to the screen.
It shows a very very blury double image; side by side. I figure it's
because the screen only accepts an interlaced signal and the card
outputs a progressive scan signal... but this is all still new to me so
maybe i got it wrong.
If i use something like Dave mentioned
http://www.analog.com/en/digital-to-analog-converters/video-encoders/ad725/products/product.html
I think it would work for what i need.

The documentation for that chip specifically identifies the need for an
interlaced VGA input at the appropriate size and frequency.

Sylvia.

 

[Jasen Betts]

On 2010-02-06, fuzzymonkey <fuzzymonkey87@hotmail.com> wrote:

Hi,
I'm trying to to get my hands on a chip that will convert a VGA signal to
PAL.
I've found a few, but they're discontinued. RsComponents, Maxim, Jaycar and
googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

Thanks

Rohm BH7236AF-E2 (farnell part number 1716147 )

This won't translate the resolution or sync rate, it'll just convert
RGBa+sync to PAL composite. However most VGAs should be capable of
the PAL sync rate



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[fuzzymonkey]

(resent coz Windows Live Mail is a crap Newsgroup client)

Wow i just realised you're Dave from the eevblog! Pays to look at peoples
signatures. Love the video blog!

I was looking a similar chip on rsComponents. So the one you suggested is
great, only problem is the minimum purchase quantity from analog.com is 100!
I only need 1 (or 2 since i'll probably destroy the first one.)



"David L. Jones" <altzone@gmail.com> wrote in message
news:0Mlbn.6713$5n.6481@newsfe23.iad...

fuzzymonkey wrote:
Hi,
I'm trying to to get my hands on a chip that will convert a VGA
signal to PAL.
I've found a few, but they're discontinued. RsComponents, Maxim,
Jaycar and googling for hours hasn't worked!

Does anyone know where i could a chip that does this?

http://www.analog.com/en/digital-to-analog-converters/video-encoders/ad725/products/product.html

Dave.

--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.eevblog.com

 

[David L. Jones]

fuzzymonkey wrote:

(resent coz Windows Live Mail is a crap Newsgroup client)

Wow i just realised you're Dave from the eevblog! Pays to look at
peoples signatures. Love the video blog!

I was looking a similar chip on rsComponents. So the one you
suggested is great, only problem is the minimum purchase quantity
from analog.com is 100! I only need 1 (or 2 since i'll probably
destroy the first one.)

You could try getting samples.
Alternatively, Farnell have it in stock in the UK.
Failing that, I might have some lying around somewhere.
Definitely got some on some old boards.

Dave.

--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.eevblog.com

 

[Sylvia Else]

On 7/02/2010 11:58 AM, fuzzymonkey wrote:

It can display NTSC or PAL and takes a composite or S-video connection.
From VGA i connected Red, Green, Blue, Ground and HSync to the screen.
It shows a very very blury double image; side by side. I figure it's
because the screen only accepts an interlaced signal and the card
outputs a progressive scan signal... but this is all still new to me so
maybe i got it wrong.

It's still going to be quite blurry even when it's working perfectly. TV
resolution just isn't that good. You will of course go the S-video
route, rather than composite video, since it produces somewhat better
results.

Sylvia.

 

[fuzzymonkey]

From the datasheet:
"The AD725 can be used to convert the analog RGB output from a
personal computer's VGA card to the NTSC or PAL television
standards. To accomplish this it is important to understand that
the AD725 requires interlaced RGB video and clock rates that
are consistent with those required by the television standards.
In most computers the default output is a noninterlaced RGB
signal at a frame rate higher than used by either NTSC or PAL."

Yup, that sucks. I know computer i'm using can't output an interlaced
signal. Suppose try and see how i can convert from progressive scan to
interlaced (and actually read the data sheet!). Even if i drop every 2nd
line to get the correct vertical resolution i'm ok with that (is it as
simple as a clock divider? i wont have a chance to try it for a while).
Otherwise i'll just give up and buy something like David Eather mentioned.

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:00ea0892$0$23817$c3e8da3@news.astraweb.com...

On 7/02/2010 11:58 AM, fuzzymonkey wrote:
Actually, that's exactly what happens now! The screen is a small LCD
from a PSone.
pic -
http://www.retroleum.co.uk/wp-content/uploads/2009/05/psonelcd_front.jpg

It can display NTSC or PAL and takes a composite or S-video connection.
From VGA i connected Red, Green, Blue, Ground and HSync to the screen.
It shows a very very blury double image; side by side. I figure it's
because the screen only accepts an interlaced signal and the card
outputs a progressive scan signal... but this is all still new to me so
maybe i got it wrong.
If i use something like Dave mentioned
http://www.analog.com/en/digital-to-analog-converters/video-encoders/ad725/products/product.html
I think it would work for what i need.

The documentation for that chip specifically identifies the need for an
interlaced VGA input at the appropriate size and frequency.

Sylvia.

 

[Sylvia Else]

On 17/02/2010 10:34 PM, fuzzymonkey wrote:

From the datasheet:
"The AD725 can be used to convert the analog RGB output from a
personal computer's VGA card to the NTSC or PAL television
standards. To accomplish this it is important to understand that
the AD725 requires interlaced RGB video and clock rates that
are consistent with those required by the television standards.
In most computers the default output is a noninterlaced RGB
signal at a frame rate higher than used by either NTSC or PAL."

They sort of imply that at least some VGA cards can be configured to
produce interlaced output with NTSC or PAL compatible timing, but I've
never come across any information about so configuring them.

Yup, that sucks. I know computer i'm using can't output an interlaced
signal. Suppose try and see how i can convert from progressive scan to
interlaced (and actually read the data sheet!). Even if i drop every 2nd
line to get the correct vertical resolution i'm ok with that (is it as
simple as a clock divider? i wont have a chance to try it for a while).
Otherwise i'll just give up and buy something like David Eather mentioned.

Even if you contrive to drop every alternate line, the pixel rate will
still be wrong, and, importantly, the vertical sync pulses will not be
set for interlaced - an interlaced field either starts or ends with a
half-line - so that the total number of lines is odd (525, or 625).

You need a scan converter - which is what David Eather pointed to, and
the cheap one (similar price to the one posted) I have produces a
correspondingly cheap output.

It's very easy to end up wasting a lot of money like this, and LCD
monitors these days can be had quite cheaply. You might be advised to
take that option.

Sylvia.

 

[fritz]

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:4b7bdb98$0$10533$c3e8da3@news.astraweb.com...

On 17/02/2010 10:34 PM, fuzzymonkey wrote:
From the datasheet:
"The AD725 can be used to convert the analog RGB output from a
personal computer's VGA card to the NTSC or PAL television
standards. To accomplish this it is important to understand that
the AD725 requires interlaced RGB video and clock rates that
are consistent with those required by the television standards.
In most computers the default output is a noninterlaced RGB
signal at a frame rate higher than used by either NTSC or PAL."

They sort of imply that at least some VGA cards can be configured to
produce interlaced output with NTSC or PAL compatible timing, but I've
never come across any information about so configuring them.

It's called TV OUT or something similar. Pretty straightforward, really.
Either your video card has it or it doesn't, simple.

 

[Sylvia Else]

On 18/02/2010 7:55 AM, fritz wrote:

"Sylvia Else"<sylvia@not.at.this.address> wrote in message
news:4b7bdb98$0$10533$c3e8da3@news.astraweb.com...
On 17/02/2010 10:34 PM, fuzzymonkey wrote:
From the datasheet:
"The AD725 can be used to convert the analog RGB output from a
personal computer's VGA card to the NTSC or PAL television
standards. To accomplish this it is important to understand that
the AD725 requires interlaced RGB video and clock rates that
are consistent with those required by the television standards.
In most computers the default output is a noninterlaced RGB
signal at a frame rate higher than used by either NTSC or PAL."

They sort of imply that at least some VGA cards can be configured to
produce interlaced output with NTSC or PAL compatible timing, but I've
never come across any information about so configuring them.

It's called TV OUT or something similar. Pretty straightforward, really.
Either your video card has it or it doesn't, simple.

A TV out socket will produce a composite video signal. A VGA output with
TV compatible timing would still produce an RGB output with separate
horizontal and vertical sync signals, but the timing would be such that
it could be converted by a circuit such as AD725 into a composite video
signal.

So they're different, and the "either has it or it doesn't" position
doesn't stand up.

Sylvia.

 

[Jasen Betts]

On 2010-02-17, fuzzymonkey <fuzzymonkey87@hotmail.com> wrote:

From the datasheet:
"The AD725 can be used to convert the analog RGB output from a
personal computer's VGA card to the NTSC or PAL television
standards. To accomplish this it is important to understand that
the AD725 requires interlaced RGB video and clock rates that
are consistent with those required by the television standards.
In most computers the default output is a noninterlaced RGB
signal at a frame rate higher than used by either NTSC or PAL."

Yup, that sucks. I know computer i'm using can't output an interlaced
signal.

It's probably just a software problem. hardware-wise all you need is a
VGA compatible video card. these cards have an interlace option, you
just need to turn it on.

Suppose try and see how i can convert from progressive scan to
interlaced (and actually read the data sheet!).

that's too much like hard work.

Even if i drop every 2nd
line to get the correct vertical resolution i'm ok with that (is it as
simple as a clock divider?

that's not going to work. you need to slow the horizontal scan rate
down and reduce the number of scan lines.

OTOH a CGA compatible video card runs at the NTSC tv sync rate,
and converted to composite that will display a raster on most PAL TVs
(I had a CGA card with a monochrome composite out in the 80s)

but seriously with a VGA card, it's just a matter of setting the right
parameters. how are you setting the currnt video mode?
(mswin? X? libvga? stm?)

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---