Michael J. Mahon

For any of you familiar with the SCART connector, here's a *very*
reasonable converter from RGB to Component video--for connecting
a IIgs to a hi-def monitor, perhaps.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=190105916343

The cost is so low, I'm not sure exactly what it is, but I'm guessing
that it either gets power from the SCART connector or the white RCA
connector is a power input (?) or ??? If it's passive, then I doubt
it would do the job.

There are other, similar, devices for auction, that clearly require
external power, but the one I saw was a reserve auction. ;-(

-michael

NadaNet file server for Apple II computers!
Home page: http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."

mdj

Michael J. Mahon wrote:
> For any of you familiar with the SCART connector, here's a *very*
> reasonable converter from RGB to Component video--for connecting
> a IIgs to a hi-def monitor, perhaps.
>
> http://cgi.ebay.com/ws/eBayISAPI.dll...m=190105916343
>
> The cost is so low, I'm not sure exactly what it is, but I'm guessing
> that it either gets power from the SCART connector or the white RCA
> connector is a power input (?) or ??? If it's passive, then I doubt
> it would do the job.

It must be. The circuitry required to convert RGB to YUV is pretty
trivial but you do need power.
There was a simple design published in one of our local hobbyist
electronics rags a couple of years back.

BTW your above link goes to an AppliCard, not said converter.

Matt

William Garber

"Michael J. Mahon" <mjmahon@aol.com> wrote in message newsYSdndlh9PuBxKPbnZ2dnUVZ_jOdnZ2d@comcast.com. ..
:
: That's annoying! I constructed a short URL in NotePad, but
: then apparently neglected to "copy" it before pasting. ;-(
:
: Here's what it should have been:
:
: http://cgi.ebay.com/ws/eBayISAPI.dll...m=150118786661
:
: Here's a link to a converter that clearly *is* powered,
: with a low starting bid, but with a reserve:
:
: http://cgi.ebay.com/ws/eBayISAPI.dll...m=330116364937

How about this one with a BUY-IT-NOW price tag.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=330095629073

William Garber
Email Address - willy46pa@garberstreet.com
Alt. Email - willy46pa@comcast.net
Web address - http://www.garberstreet.com

mdj

On May 7, 8:38 am, "Michael J. Mahon" <mjma...@aol.com> wrote:

> I was thinking that the white RCA connector could also be a sync
> output... But, IIRC, the SCART connector does have power, right?

Unfortunately, no. It provides stereo sound in/out, composite video in/
out, and RGB in/out. The later revisions of the standard allow the RGB
signal pins to carry either YUV or S-Video. IIRC, YUV isn't even a
part of the standard.

There's also pins for the D2B automation bus and a signalling pin for
16:9/4:3 source identification.

So that white connector could also be composite sync input. Perhaps
the power connection is obscured somehow.

Matt

Michael J. Mahon

William Garber wrote:
> "Michael J. Mahon" <mjmahon@aol.com> wrote in message newsYSdndlh9PuBxKPbnZ2dnUVZ_jOdnZ2d@comcast.com. ..
> :
> : That's annoying! I constructed a short URL in NotePad, but
> : then apparently neglected to "copy" it before pasting. ;-(
> :
> : Here's what it should have been:
> :
> : http://cgi.ebay.com/ws/eBayISAPI.dll...m=150118786661
> :
> : Here's a link to a converter that clearly *is* powered,
> : with a low starting bid, but with a reserve:
> :
> : http://cgi.ebay.com/ws/eBayISAPI.dll...m=330116364937
>
> How about this one with a BUY-IT-NOW price tag.
>
> http://cgi.ebay.com/ws/eBayISAPI.dll...m=330095629073

Aha! So we can make an educated guess about what the reserve is...

Still, not too bad.

-michael

NadaNet file server for Apple II computers!
Home page: http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."

Michael J. Mahon

mdj wrote:
> On May 7, 8:38 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
>
>>I was thinking that the white RCA connector could also be a sync
>>output... But, IIRC, the SCART connector does have power, right?
>
>
> Unfortunately, no. It provides stereo sound in/out, composite video in/
> out, and RGB in/out. The later revisions of the standard allow the RGB
> signal pins to carry either YUV or S-Video. IIRC, YUV isn't even a
> part of the standard.
>
> There's also pins for the D2B automation bus and a signalling pin for
> 16:9/4:3 source identification.
>
> So that white connector could also be composite sync input. Perhaps
> the power connection is obscured somehow.

OK, my apologies...I thought all those RCA jacks were *outputs*!
After all, it does say RGB *to* component, and SCART is RGB, right?

And it also says:

* BRAND NEW; Scart (male) to Component (female) Adapter.
* For 'RGB' scart video signal to high quality 'Y/U/V' component video
signal.
* Signal output from DVD players, Freeview, Sky or Sky+ set-top boxes
to Component Video.

That sure *sounds* like it accepts an RGB signal on the SCART side
and outputs a Component signal on the RCA side.

I thought that SCART was also an *output* connector for AV equipment,
and that it would supply RGB that this box would convert to component.
(And with all those pins, not supplying a little power seems like an
oversight...)

Does anyone know what this $5 thing actually does?
(I'm pretty sure that the $60 box does what I described.)

In any event, this would be a straightforward way to drive a modern
TV from a IIgs RGB signal, perhaps.

-michael

NadaNet file server for Apple II computers!
Home page: http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."

jsnospam@cimmeri.com

As I have a Keene Scart RGB->YUV converter, I can say that mine
requires power, and only has the three YPbPr outputs. The white one
on this one is probably composite sync or compvid out... as Scart has
these on the input side.

Like another person wrote, there's probably an obscured power input.
Not sure any of the Scart signal pins that have higher voltages (12v,
for instance) can supply enough current to power the opamps.

~ J

Charlie

"Michael J. Mahon" <mjmahon@aol.com> wrote in message
news:5vSdnYkGg6mtYqPbnZ2dnUVZ_q2pnZ2d@comcast.com. ..
> mdj wrote:
>> On May 7, 8:38 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>>
>>
>>>I was thinking that the white RCA connector could also be a sync
>>>output... But, IIRC, the SCART connector does have power, right?
>>
>>
>> Unfortunately, no. It provides stereo sound in/out, composite video in/
>> out, and RGB in/out. The later revisions of the standard allow the RGB
>> signal pins to carry either YUV or S-Video. IIRC, YUV isn't even a
>> part of the standard.
>>
>> There's also pins for the D2B automation bus and a signalling pin for
>> 16:9/4:3 source identification.
>>
>> So that white connector could also be composite sync input. Perhaps
>> the power connection is obscured somehow.
>
> OK, my apologies...I thought all those RCA jacks were *outputs*!
> After all, it does say RGB *to* component, and SCART is RGB, right?
>
> And it also says:
>
> * BRAND NEW; Scart (male) to Component (female) Adapter.
> * For 'RGB' scart video signal to high quality 'Y/U/V' component video
> signal.
> * Signal output from DVD players, Freeview, Sky or Sky+ set-top boxes
> to Component Video.
>
> That sure *sounds* like it accepts an RGB signal on the SCART side
> and outputs a Component signal on the RCA side.
>
> I thought that SCART was also an *output* connector for AV equipment,
> and that it would supply RGB that this box would convert to component.
> (And with all those pins, not supplying a little power seems like an
> oversight...)
>
> Does anyone know what this $5 thing actually does?
> (I'm pretty sure that the $60 box does what I described.)
>
> In any event, this would be a straightforward way to drive a modern
> TV from a IIgs RGB signal, perhaps.

Michael,

Okay, I'm a little confused. What is the difference between RGB component
video and Y/U/V component video? And more important to me, would either one
of the boxes (assuming they do what they advertise) give me a better screen
image than just running the IIgs output into my Monitor/TV with Roger
Johnstone's IIgs to SCART cable? As it stands now I get a usable but not
perfect picture. The only problem seems to be in the transition from one
color to another horizontally. For instance, if you have a line of
horizontal black pixels which turn to white there will be one pixel at the
transition that is gray. This creates a horizontal ghosting effect that can
be reduced by judicious adjusting of the contrast and sharpness, but some
color combinations are worse than others. I had the impression from past
threads that this ghosting effect was caused by the monitor not being able
to sync with the IIgs signal frequency.

My monitor/TV (Samsung SyncMaster 940mw) will accept several types of video
input including both SCART and component video but to further confuse me the
component video input is listed as Pr, Pb, Y.

Charlie

Michael J. Mahon

Charlie wrote:
> "Michael J. Mahon" <mjmahon@aol.com> wrote in message
> news:5vSdnYkGg6mtYqPbnZ2dnUVZ_q2pnZ2d@comcast.com. ..
>
>>mdj wrote:
>>
>>>On May 7, 8:38 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>>>
>>>
>>>
>>>>I was thinking that the white RCA connector could also be a sync
>>>>output... But, IIRC, the SCART connector does have power, right?
>>>
>>>
>>>Unfortunately, no. It provides stereo sound in/out, composite video in/
>>>out, and RGB in/out. The later revisions of the standard allow the RGB
>>>signal pins to carry either YUV or S-Video. IIRC, YUV isn't even a
>>>part of the standard.
>>>
>>>There's also pins for the D2B automation bus and a signalling pin for
>>>16:9/4:3 source identification.
>>>
>>>So that white connector could also be composite sync input. Perhaps
>>>the power connection is obscured somehow.
>>
>>OK, my apologies...I thought all those RCA jacks were *outputs*!
>>After all, it does say RGB *to* component, and SCART is RGB, right?
>>
>>And it also says:
>>
>>* BRAND NEW; Scart (male) to Component (female) Adapter.
>>* For 'RGB' scart video signal to high quality 'Y/U/V' component video
>> signal.
>>* Signal output from DVD players, Freeview, Sky or Sky+ set-top boxes
>> to Component Video.
>>
>>That sure *sounds* like it accepts an RGB signal on the SCART side
>>and outputs a Component signal on the RCA side.
>>
>>I thought that SCART was also an *output* connector for AV equipment,
>>and that it would supply RGB that this box would convert to component.
>>(And with all those pins, not supplying a little power seems like an
>>oversight...)
>>
>>Does anyone know what this $5 thing actually does?
>>(I'm pretty sure that the $60 box does what I described.)
>>
>>In any event, this would be a straightforward way to drive a modern
>>TV from a IIgs RGB signal, perhaps.
>
>
> Michael,
>
> Okay, I'm a little confused. What is the difference between RGB component
> video and Y/U/V component video?

RGB is one thing, Component is another--and Y/U/V is another way of
saying "component".

"Component" is not commonly used to refer to RGB.

RGB is three, high-bandwidth analog video signals, one per primary color
of the display device.

Component refers to three analog signals: the high-bandwidth luminance
signal (Y), and the (usually lower bandwidth) color difference signals
called B-Y (or Pb or U) and R-Y (or Pr or V). (These different names
actually refer to different matrix factors used in forming the signals
and their levels, so they are not *really* identical, though their
usage is quite similar.)

RGB is a standard native to tri-color displays and computer graphics
systems, while component video is native to video recording and
transmission systems. Component video, with its typically reduced
bandwidth chroma channels, is better suited to video transmission.

> And more important to me, would either one
> of the boxes (assuming they do what they advertise) give me a better screen
> image than just running the IIgs output into my Monitor/TV with Roger
> Johnstone's IIgs to SCART cable?

No, direct analog RGB output to an RGB input is the best you can do.

> As it stands now I get a usable but not
> perfect picture. The only problem seems to be in the transition from one
> color to another horizontally. For instance, if you have a line of
> horizontal black pixels which turn to white there will be one pixel at the
> transition that is gray. This creates a horizontal ghosting effect that can
> be reduced by judicious adjusting of the contrast and sharpness, but some
> color combinations are worse than others. I had the impression from past
> threads that this ghosting effect was caused by the monitor not being able
> to sync with the IIgs signal frequency.

I presume you are using a digital monitor, and you are correct, the
"intermediate" value pixel is the result of the sampling clock of the
monitor not being locked to the dot clock of the IIgs. If the pattern
of gray pixels is constant and consistent over the width of the display,
then your monitor may have locked to a multiple of the dot clock.

> My monitor/TV (Samsung SyncMaster 940mw) will accept several types of video
> input including both SCART and component video but to further confuse me the
> component video input is listed as Pr, Pb, Y.

Those are the common names for the "components" of "component video".

The reason for my interest in good, inexpensive RGB to component
converters is that in the US, HD monitors typically do not have RGB
inputs, but they often do have component inputs. Since component
signals can be created from RGB signals by analog matrixing (combination
with specific weighting factors), such converters are, in principle,
very simple. Unfortunately, they also seem to be relatively low volume,
so their simplicity often is not reflected in their price.

-michael

NadaNet file server for Apple II computers!
Home page: http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."

nyder

On May 7, 1:00 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
> Charlie wrote:
> > "Michael J. Mahon" <mjma...@aol.com> wrote in message
> >news:5vSdnYkGg6mtYqPbnZ2dnUVZ_q2pnZ2d@comcast.com ...
>
> >>mdj wrote:
>
> >>>On May 7, 8:38 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
> >>>>I was thinking that the white RCA connector could also be a sync
> >>>>output... But, IIRC, the SCART connector does have power, right?
>
> >>>Unfortunately, no. It provides stereo sound in/out, composite video in/
> >>>out, and RGB in/out. The later revisions of the standard allow the RGB
> >>>signal pins to carry either YUV or S-Video. IIRC, YUV isn't even a
> >>>part of the standard.
>
> >>>There's also pins for the D2B automation bus and a signalling pin for
> >>>16:9/4:3 source identification.
>
> >>>So that white connector could also be composite sync input. Perhaps
> >>>the power connection is obscured somehow.
>
> >>OK, my apologies...I thought all those RCA jacks were *outputs*!
> >>After all, it does say RGB *to* component, and SCART is RGB, right?
>
> >>And it also says:
>
> >>* BRAND NEW; Scart (male) to Component (female) Adapter.
> >>* For 'RGB' scart video signal to high quality 'Y/U/V' component video
> >> signal.
> >>* Signal output from DVD players, Freeview, Sky or Sky+ set-top boxes
> >> to Component Video.
>
> >>That sure *sounds* like it accepts an RGB signal on the SCART side
> >>and outputs a Component signal on the RCA side.
>
> >>I thought that SCART was also an *output* connector for AV equipment,
> >>and that it would supply RGB that this box would convert to component.
> >>(And with all those pins, not supplying a little power seems like an
> >>oversight...)
>
> >>Does anyone know what this $5 thing actually does?
> >>(I'm pretty sure that the $60 box does what I described.)
>
> >>In any event, this would be a straightforward way to drive a modern
> >>TV from a IIgs RGB signal, perhaps.
>
> > Michael,
>
> > Okay, I'm a little confused. What is the difference between RGB component
> > video and Y/U/V component video?
>
> RGB is one thing, Component is another--and Y/U/V is another way of
> saying "component".
>
> "Component" is not commonly used to refer to RGB.
>
> RGB is three, high-bandwidth analog video signals, one per primary color
> of the display device.
>
> Component refers to three analog signals: the high-bandwidth luminance
> signal (Y), and the (usually lower bandwidth) color difference signals
> called B-Y (or Pb or U) and R-Y (or Pr or V). (These different names
> actually refer to different matrix factors used in forming the signals
> and their levels, so they are not *really* identical, though their
> usage is quite similar.)
>
> RGB is a standard native to tri-color displays and computer graphics
> systems, while component video is native to video recording and
> transmission systems. Component video, with its typically reduced
> bandwidth chroma channels, is better suited to video transmission.
>
> > And more important to me, would either one
> > of the boxes (assuming they do what they advertise) give me a better screen
> > image than just running the IIgs output into my Monitor/TV with Roger
> > Johnstone's IIgs to SCART cable?
>
> No, direct analog RGB output to an RGB input is the best you can do.
>
> > As it stands now I get a usable but not
> > perfect picture. The only problem seems to be in the transition from one
> > color to another horizontally. For instance, if you have a line of
> > horizontal black pixels which turn to white there will be one pixel at the
> > transition that is gray. This creates a horizontal ghosting effect that can
> > be reduced by judicious adjusting of the contrast and sharpness, but some
> > color combinations are worse than others. I had the impression from past
> > threads that this ghosting effect was caused by the monitor not being able
> > to sync with the IIgs signal frequency.
>
> I presume you are using a digital monitor, and you are correct, the
> "intermediate" value pixel is the result of the sampling clock of the
> monitor not being locked to the dot clock of the IIgs. If the pattern
> of gray pixels is constant and consistent over the width of the display,
> then your monitor may have locked to a multiple of the dot clock.
>
> > My monitor/TV (Samsung SyncMaster 940mw) will accept several types of video
> > input including both SCART and component video but to further confuse me the
> > component video input is listed as Pr, Pb, Y.
>
> Those are the common names for the "components" of "component video".
>
> The reason for my interest in good, inexpensive RGB to component
> converters is that in the US, HD monitors typically do not have RGB
> inputs, but they often do have component inputs. Since component
> signals can be created from RGB signals by analog matrixing (combination
> with specific weighting factors), such converters are, in principle,
> very simple. Unfortunately, they also seem to be relatively low volume,
> so their simplicity often is not reflected in their price.
>
> -michael
>
> NadaNet file server for Apple II computers!
> Home page: http://members.aol.com/MJMahon/
>
> "The wastebasket is our most important design
> tool--and it's seriously underused."



Does the IIGS output analog or digital RGB?