North American RGB standard jacks?

Started by Lost Monkey, June 01, 2005, 11:57:35 PM

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Lost Monkey

I just picked up a 26" RCA Dimensia, which I expect to use in a MAME cabinet...

The RGB input is a set of 4 rca jacks labelled r,g,b and enable.  What I am wondering is, is this the "standard" for North American monitors with RGB capabilities?  Before I go through the trouble of building some cables and connectors (not to mention the system mods), I would like to know if I replace this monitor, will I have to start all over again with the cables, etc...  If it is not "standard" I will just make a box and run standard rca cables from it...



viletim~

I don't have first hand experience (I don't live in America) but I believe there's no mechanical RGB input standard in the US. Monitors use Phono, BNC, UHF, Sub-D,variety of DIN connectors, etc. Differences arn't entirely mechanical either - sync formats can vary too - seperate, composite, on green, etc

Endymion

There is no standard, you will absolutely have to roll your own. The closest thing I have seen is that Sony uses a longer DB15 (two rows of pins, not 3 as with VGA) for all of their PVM and GVM monitors, but that's it. All others are very inconsistent, even among the same manufacturer--NEC has monitors that use a long, weirdly shaped 32-pin (I think) and others that use a DB9. That's one reason that a self-made patch is desirable--that way you don't wind up hacking your RGB cables to pieces. Get a SCART multibox for a few pounds and modify its connector for your monitor. Then you can just plug in your SCART cables as you acquire them.

Akir

Standards? In America? You've got to be joking. Most of the people here are too full of themselves to even get together to even talk about a standard. Trust me - I'd know; I'm an American. But if anything can be called a standard, it would be DVI, and in the near future, HDMI.

RGB32E

#4
Oh come on Akir ;P ... At least in the land of NTSC, HDTV standards have been set... unlike most of the world (Europe *cough*).  Besides, there hasn't been any major consumer level electronics to necessitate a standard for RGB (besides video game consoles).  

Having a standard for RGB via PAL kind of sucks anyways, as 50Hz gaming can be tough on the eyes!  (I am aware that PAL60 exists, but is not always applicable).  In the PAL part of the world, do many devices actually carry RGB over SCART cables (other than games and perhaps DVD players)?

HDMI has replaced DVI for HDTVs and DVD players.  I am not aware of any new US products in the past year or so that incorporate DVI (other than PC graphics cards).

Are most of you posters living in non-NTSC regions?  It's funny to read the information inaccuracies between regions.  </VT>

=P

dj898

Quote
Having a standard for RGB via PAL kind of sucks anyways, as 50Hz gaming can be tough on the eyes!  (I am aware that PAL60 exists, but is not always applicable).  In the PAL part of the world, do many devices actually carry RGB over SCART cables (other than games and perhaps DVD players)?
on telly my old man used to have before replacing with Fujitsu PDP it has three scart at the back and one was in red colour and according to the manual that one is RGB compatible... the TV was Pioneer RPTV in the size of medium size freezer that he bought in mid 90s... :P

being a fool didn't ask him to give it to me - he put it outside on council collection day and someone picked up in no time...(must brought the ute as it wasn't small thing you can fit into a car boot.)

Aidan

#6
QuoteIn the PAL part of the world, do many devices actually carry RGB over SCART cables (other than games and perhaps DVD players)?
In the UK, most DVD players (including the bargin basement ones), many satellite and terrestrial set top boxes (Again, including the cheap ones) support RGB output. Video recorders only really operate in the realm of s-video, as they don't process RGB.

What else would you plug into a TV?
[ Not an authoritive source of information. ]

Endymion

QuoteHaving a standard for RGB via PAL kind of sucks anyways, as 50Hz gaming can be tough on the eyes!  (I am aware that PAL60 exists, but is not always applicable).
Hm, I thought RGB solved the 50Hz problem? Although I've never had to deal with it myself I seem to remember reading a lot of blokes wanting RGB to get rid of the border consequences of 50Hz PAL?

phreak97

rgb solves the pal/ntsc problem, but not the 50/60Hz problem.

Aidan

As phreak97 points out, it solves the problem of NTSC vs PAL colour encoding, as it's all provided seperately. It doesn't solve any issues of frame rates however, so it doesn't solve the border problem.

What it does allow is for a signal with NTSC timing (60Hz field rate) to be (probably) displayed on a device that otherwise couldn't handle the NTSC signal colour encoding. That and it generally provides the sharpest picture.
[ Not an authoritive source of information. ]

Lost Monkey

I finally got a chance to hook my Gen 1 up to the Dimensia...

The picture is nice and stable, but also very low colour...

I had to add the RGB (rca) jacks to the back of the Gen, as I don't have any cables compatible with the A/V port... so I figured I might have a wiring problem -

- all wiring has now been checked and re-checked.
- everything is grounded - using pin 24 of the CXA1145.
- the monitor seems to prefer to use the composite output for sync - I get no picture using the sync off the A/V port.
- one thing that "alarms" me, is that the RGB signals all show as "shorted" (to each other) with my multimeter when the cables are plugged into the monitor - but not when they are not plugged into it.  Could this be a problem? (if so, then the monitor is good for shit as far as RGB goes...)
- I have also tried sending sync and composite video to the enable jack - no dice, in fact no picture at all...

Also, being that this is a 1986 television/monitor, is it possible that it doesn't display high colour in RGB? ( <_<


Lost Monkey

Here is what the output looks like:



and here are the inputs on the monitor:





viletim!

Lost Monkey,
As I understand it, this Dimensia thing has both composite and RGB inputs. Correct?

QuoteThe picture is nice and stable, but also very low colour...
That's not a normal failure mode for and RGB monitor (unless the brightness is abnormaly high). I'd say that's definately a wiring problem. Check all the usual things: Is ground really ground (use the big ground plane rather than a SMD chip pin)? Are the required components in series with the signal (resistor+cap)? Are you sure your pinout is correct?

Quote- one thing that "alarms" me, is that the RGB signals all show as "shorted" (to each other) with my multimeter when the cables are plugged into the monitor - but not when they are not plugged into it. Could this be a problem? (if so, then the monitor is good for shit as far as RGB goes...)
Were you using the diode check/beeper mode? Switch to ohmmeter mode. You should measure a resistance of 75 ohms between the input pin and ground. Keeping the input Z low reduces noise and allows the use of impedance matched cables/sources. It's all normal. If you're actualy measureing something closer to 0 ohms, then there's a problem. :)

Quote- I have also tried sending sync and composite video to the enable jack - no dice, in fact no picture at all...
This is to switch between RGB and composite I assume... The first thing I would do is measure the voltage on this jack while the monitor is on. If you measure anything then perhaps it simply requires the signal to be grounded to switch over. If that doesn't work then it's likely that some kind of switching voltage needs to be fed to it. Measure the input resistance. If it's low, like 75 ohms, then the voltage probably needs to be low, a volt or so. If it's high (1k to infinity) then try feeding 5 volts to this input.

QuoteAlso, being that this is a 1986 television/monitor, is it possible that it doesn't display high colour in RGB?
nah...

Endymion

#13
I don't like the look of that "TEXT/GRAPHICS" set. Just looking at that I would suspect this could be a digital RGB monitor. Have you googled for the model number?

Lost Monkey

QuoteI don't like the look of that "TEXT/GRAPHICS" set. Just looking at that I would suspect this could be a digital RGB monitor. Have you googled for the model number?
This is all I've found so far... I am googling for a manual...

http://www.cedmagic.com/museum/dimensia/fkc2600-1.html

Endymion

Did you do anything about this?

QuoteRGB/Enable:
TTL Compatible
Hi (color on) = min 2.4 V (no current required as Monitor has internal 3.65 V pull up voltage through 65 Ohm resistor)
Lo (color off) = less than 1.5 V; less than 50 Ohms impedance; able to draw minimum 30 ma.

emuman100

I'm in the US, and the Sony PVM monitors at work have 75 ohm BNCs that can input RGBS. My "standard" is 75 ohm BNCs, but on the video generating devices I either go with BNCs, DB9, or DIN. On say a NES, I'd put BNC for RGB, with a NES2 I'd put DIN or DB9 because of space constraints. Anything that uses VESA video modes or higher resolution/frequency I go with the common HD15 connector.

Lost Monkey

QuoteDid you do anything about this?

QuoteRGB/Enable:
TTL Compatible
Hi (color on) = min 2.4 V (no current required as Monitor has internal 3.65 V pull up voltage through 65 Ohm resistor)
Lo (color off) = less than 1.5 V; less than 50 Ohms impedance; able to draw minimum 30 ma.
I didn't see that until around the time you posted...

I don't understand what it means.. do I have to feed >2.4V to the enable jack?


Lost Monkey

#18
Quote
Quote- I have also tried sending sync and composite video to the enable jack - no dice, in fact no picture at all...
This is to switch between RGB and composite I assume... The first thing I would do is measure the voltage on this jack while the monitor is on. If you measure anything then perhaps it simply requires the signal to be grounded to switch over. If that doesn't work then it's likely that some kind of switching voltage needs to be fed to it. Measure the input resistance. If it's low, like 75 ohms, then the voltage probably needs to be low, a volt or so. If it's high (1k to infinity) then try feeding 5 volts to this input.

QuoteAlso, being that this is a 1986 television/monitor, is it possible that it doesn't display high colour in RGB?
nah...
The RGB and enable jacks on the monitor all measure 3.5-3.7 volts...  

Grounding the enable jack, leaves the monitor in RGB mode (the RGB indicator stays lit) but the display to the screen is clearly the composite input.  With nothing in the enable jack, the RGB mode remains, and the display switches to the "low colour" RGB mode I have been experiencing...


QuoteRGB/Enable:
TTL Compatible
Hi (color on) = min 2.4 V (no current required as Monitor has internal 3.65 V pull up voltage through 65 Ohm resistor)



:P

How about I try adding a 65 Ohm resistor to my RG&B lines...

NFG

That's a Digital monitor (TTL = digital).  That's why you're only getting one shade of each colour: red, green or blue.  It's either on or off.  The most you'll get out of this is 8 colours.  Personally I'm surprised it works at all.

Lost Monkey

#20
What I don't get, is, how can this monitor be (CGA?) TTL digital RGB, but still function normally with composite and RF?:blink:

I can't find a manual for it anywhere either...

Plus I just received enough supplies to add RGB jacks to about 10 of my systems....  :angry:  

Endymion

Get what you can for it and move on, the sooner it's out of your hair the better you'll feel and can start work on something with legs. You can get a great NEC monitor that does RGB and VGA if you look for my recent post on a Mitsubishi monitor I just acquired, also in this forum.

Computolio


   If you can't find SCART connectors or you're hooking up something that has a seperated sync signal (like an old computer or something), then just use JRGB-15. It's kind of sparse (and you'll want to use pin 9 for a switching/sync chip power voltage), but it gets the job done and it was a standard somewhere at some time. It's also dead easy to find the parts for (unlike SCART).

Aidan

QuoteWhat I don't get, is, how can this monitor be (CGA?) TTL digital RGB, but still function normally with composite and RF?:blink:
Yup, that'd be just fine. I'd hazard a guess that the RGB input you're looking at was probably originally designed to allow a basic computer overlay on an existing video stream. Unless you feel like making modifications to the internal RGB circuit, then the monitor isn't suitable for an analog RGB input.
[ Not an authoritive source of information. ]

Lost Monkey

Thanks for all the help folks...  B)

I do have another use for this monitor anyway - I am going to make an Atari 2600/7800 cabinet.  I have a Cuttle Cart 2, and the composite output of a 7800 is more than adequate.

viletim!

QuoteThe RGB and enable jacks on the monitor all measure 3.5-3.7 volts...
Does this mean that the picture goes white when the monitor's in RGB mode and there's nothing connected? :)

Lost Monkey

#26
Quote
QuoteThe RGB and enable jacks on the monitor all measure 3.5-3.7 volts...
Does this mean that the picture goes white when the monitor's in RGB mode and there's nothing connected? :)
Actually, maybe.. it won't go into RGB mode unless there is a signal on the RGB jacks... so there is no way to tell...

The way this particular monitor works is:

You plug in the RGB and Composite video cables...

Turn on the (in this case) Genesis.

The composite image appears on the screen for about 10 seconds, then the low colour RGB image appears and the "RGB" indicator light on the control panel lights up...  Why it takes so long is beyond me...

You can't actually select RGB mode via  a switch...