WORK IN PROGRESS
Welcome to the Retro AV thread, here to help you get the best picture quality out of your retro consoles. Using a CRT? A framemeister to a modern LCD? Or maybe an OSSC? We'll do our best to help you get the best image quality out of how ever you play your classic systems.
Quick note I will be updating this OT in the coming days but I wanted to get something up quickly. I figured it would be good to start with a crash course on Analog video Signals. I plan on adding sections for Upscalers (framemeister, ossc), and for CRTs. Along with touching on FPGA and HDMI mods.
Crash course in analog video signals and quality
RF (Radio frequency modulation): This is at the very bottom of the quality ladder. This takes all your audio and video signals, modulates them into a radio frequency and sends them down a single wire. Lots of artifacts like color bleed occur, dot crawl and others. It's just an overall poor quality signal.
Composite Video: A slight step above RF, this still jams all of your video signals down one line but the audio is separated out, and we're not modulating into a radio frequency any more. You still get artifacts like color bleed and dot crawl from this, with an overall blurry picture, but its a step up from RF.
S-Video: Now we're starting to get some where. S-Video separates the video signal into two parts. You have the luminance (or the black and white part of the picture), and you have the chrominance (the color part of the picture, both saturation and hue). With sync being carried along on the luma line. This is a giant step over composite video, and some feel the biggest leap as you move up in quality. On a really high quality CRT you may be happy with just S-Video. Though color resolution takes a little bit of a hit here, compared to what we have coming next.
Component video: This was the best analog signal standard US TVs ever saw. Technically component video can mean any video signal that has been broken out into its separate components but here we're specifically talking about the YPbPr standard. The YPbPr standard breaks the video signal into 3 parts. Here we see luminance being used again (the Y), the difference between blue and luma (the Pb) and the difference between red and luma (the Pr). With sync again riding along with its buddy luminance. I should note here that YPbPr is analog and the digital equivalent would be YCbCr. YPbPr offers enough separation that no color multiplexing is needed and the quality of the image should be nearly identical to the source. This offers fantastic picture quality, with none of the artifacts or flaws seen in the first 3 standards. It's almost identical to RGB.
RGB Video: RGB is a type of component video, but its not the component video we think of in the US when some one says component video. Not available on consumer CRTs in the US, professional models, Computer Monitors, and Consumer grade CRTs in Europe and Japan all have different ways of accepting RGB Video. With RGB your video signal is being broken out into it's most basic components, Red, Green, and Blue. Sync here can be a bit more complicated. You can carry sync on the composite video line, a Luma line, on it's own composite sync line (combing the horizontal and vertical syncs) or Horizontal and Vertical each getting their own line (like with VGA). I believe some devices even support sync on green. This is the signal at it's purest, no conversions, no modulating, just the pure image signal as it was created.
Let's talk about sync baby. As you've seen sync can be carried to devices in a couple of different ways, and depending on how it gets there it can cause some visual issues. For most consumer level devices, (computer monitors being the big exception) they want the horizontal and vertical syncs combined. A sync on composite signal (this is sync traveling along with composite video) in a not properly shielded cable can cause an almost dithered or checkerboard pattern to appear, specially in sections of solid color. This should not happen with sync on luma (sync travelling with the luma signal). The ideal is composite sync (not the same as sync on composite) also known as c-sync, or pure sync. This is where the Horizontal and Vertical sync signals travel on their own line. Some devices need to be modded for c-sync or have issues with c-sync, and sync on luma in these cases would do you fine.
A quick mention on resolution. It should be noted that RF, Composite Video, and S-Video all top out at 240p/480i resolution. With RGB and Component being able to support resolutions higher than this. Limitations on resolution output using RGB or Component is going to be based on individual devices.
Let's talk connectors for a moment. How do you connect these different signals to your TV, Upscaler, etc. RF uses the old coaxial connector. Like what your cable internet or cable tv comes over.
Composite video, and Component video use standard RCA connectors. Yes even though the signal and quality is vastly different both are sent over RCA connectors. Which is also typical for audio signals being paired with Composite Video, S-Video, and Component Video. The color of the cable end doesn't matter. A yellow cable can send a composite video signal or it can send the Pr signal of component video, or the left audio signal.
A quick note about D terminal, in Japan the standard for sending a YPbPr signal became the D terminal connector instead of on RCA cables. I bring this up because the Framemeister uses a D-Terminal connector, and if you plan on using it with your RCA style component connectors, you will need an adapter.
And a note about BNC connectors. You'll find these on professional video equipment, so like PVMs and BVMs. They can carry a variety of signals, and the easiest way to think of them is professional RCA connectors. Though it does go a bit beyond that. For basic info purposes though that should work.
S-Video has it's own connector it is a little 4 pin din connector. This carries ground and the split video signal.
SCART and JP21. Both of these connectors can carry a wide array of signals. They are both 21 pin connectors, and in some ways think of them as the HDMI connector of the analog world. They do have different pin outs so DO NOT mix JP21 and SCART, pick one standard and stick with it for everything. While SCART and JP21 can carry RGB, just because a cable is SCART or JP21 doesn't mean it's an RGB cable. These could be composite video or s-video cables as well. One of the really nice things about these connector standards is that using one connector can connector your video lines, sync, and audio. You may be saying hey that kind of sounds like RF, but it is very different. In SCART and JP21 each of those signals is given their own line to ride down, vs all being combined into 1 wire. When buying SCART or JP21 cables, you want to make sure you know what you're buying. Like I said a SCART cable can be RGB, Composite Video, or S-Video, and it could be c-sync, sync on luma, or sync on composite.
SCART has kind of become the RGB standard in retro gaming. Its much easier to find switches, and other devices using SCART vs JP21.
Awhile back I made a chart showing the info for as many systems as I could and what was the best video signal they supported both stock and modded.
I need to include some updates to it and hopefully I can get to that in the next few days and then I'll replace this image, but it should give you a rough idea.
Other resources
Where can I get some awesome cables for my systems? Are there any recommended sellers?
You're in luck as there are a couple good places to order from online.
For RGB cables
https://www.retrogamingcables.co.uk/ A UK based seller, that does ship internationally
https://retro-access.com/ This is the US seller that used to be retro_console_accessories on ebay.
Component cables for older consoles
HDRetrovision makes a great line of cables that convert the RGB signal to component, YPbPr.
http://www.hdretrovision.com/
What about further material for learning about this.
There are some great resources out there for learning more about this stuff.
http://retrorgb.com/ Is a fantastic website with even more of this info, and Bob also does a weekly retro roundup on his youtube channel https://www.youtube.com/channel/UCLPIbBCKVH2uKGm5C4sOkew?&ab_channel=RetroRGB
You also have My Life in Gaming's youtube channel, and specifically their RGB Masterclass videos.
https://www.youtube.com/channel/UCpvtp7mH0Cdq8FQUxcjDq0Q?&ab_channel=MyLifeinGaming
A good video about Luma and Chroma from Displaced Gamers.
youtu.be
Welcome to the Retro AV thread, here to help you get the best picture quality out of your retro consoles. Using a CRT? A framemeister to a modern LCD? Or maybe an OSSC? We'll do our best to help you get the best image quality out of how ever you play your classic systems.
Quick note I will be updating this OT in the coming days but I wanted to get something up quickly. I figured it would be good to start with a crash course on Analog video Signals. I plan on adding sections for Upscalers (framemeister, ossc), and for CRTs. Along with touching on FPGA and HDMI mods.
Crash course in analog video signals and quality
RF (Radio frequency modulation): This is at the very bottom of the quality ladder. This takes all your audio and video signals, modulates them into a radio frequency and sends them down a single wire. Lots of artifacts like color bleed occur, dot crawl and others. It's just an overall poor quality signal.
Composite Video: A slight step above RF, this still jams all of your video signals down one line but the audio is separated out, and we're not modulating into a radio frequency any more. You still get artifacts like color bleed and dot crawl from this, with an overall blurry picture, but its a step up from RF.
S-Video: Now we're starting to get some where. S-Video separates the video signal into two parts. You have the luminance (or the black and white part of the picture), and you have the chrominance (the color part of the picture, both saturation and hue). With sync being carried along on the luma line. This is a giant step over composite video, and some feel the biggest leap as you move up in quality. On a really high quality CRT you may be happy with just S-Video. Though color resolution takes a little bit of a hit here, compared to what we have coming next.
Component video: This was the best analog signal standard US TVs ever saw. Technically component video can mean any video signal that has been broken out into its separate components but here we're specifically talking about the YPbPr standard. The YPbPr standard breaks the video signal into 3 parts. Here we see luminance being used again (the Y), the difference between blue and luma (the Pb) and the difference between red and luma (the Pr). With sync again riding along with its buddy luminance. I should note here that YPbPr is analog and the digital equivalent would be YCbCr. YPbPr offers enough separation that no color multiplexing is needed and the quality of the image should be nearly identical to the source. This offers fantastic picture quality, with none of the artifacts or flaws seen in the first 3 standards. It's almost identical to RGB.
RGB Video: RGB is a type of component video, but its not the component video we think of in the US when some one says component video. Not available on consumer CRTs in the US, professional models, Computer Monitors, and Consumer grade CRTs in Europe and Japan all have different ways of accepting RGB Video. With RGB your video signal is being broken out into it's most basic components, Red, Green, and Blue. Sync here can be a bit more complicated. You can carry sync on the composite video line, a Luma line, on it's own composite sync line (combing the horizontal and vertical syncs) or Horizontal and Vertical each getting their own line (like with VGA). I believe some devices even support sync on green. This is the signal at it's purest, no conversions, no modulating, just the pure image signal as it was created.
Let's talk about sync baby. As you've seen sync can be carried to devices in a couple of different ways, and depending on how it gets there it can cause some visual issues. For most consumer level devices, (computer monitors being the big exception) they want the horizontal and vertical syncs combined. A sync on composite signal (this is sync traveling along with composite video) in a not properly shielded cable can cause an almost dithered or checkerboard pattern to appear, specially in sections of solid color. This should not happen with sync on luma (sync travelling with the luma signal). The ideal is composite sync (not the same as sync on composite) also known as c-sync, or pure sync. This is where the Horizontal and Vertical sync signals travel on their own line. Some devices need to be modded for c-sync or have issues with c-sync, and sync on luma in these cases would do you fine.
A quick mention on resolution. It should be noted that RF, Composite Video, and S-Video all top out at 240p/480i resolution. With RGB and Component being able to support resolutions higher than this. Limitations on resolution output using RGB or Component is going to be based on individual devices.
Let's talk connectors for a moment. How do you connect these different signals to your TV, Upscaler, etc. RF uses the old coaxial connector. Like what your cable internet or cable tv comes over.
Composite video, and Component video use standard RCA connectors. Yes even though the signal and quality is vastly different both are sent over RCA connectors. Which is also typical for audio signals being paired with Composite Video, S-Video, and Component Video. The color of the cable end doesn't matter. A yellow cable can send a composite video signal or it can send the Pr signal of component video, or the left audio signal.
A quick note about D terminal, in Japan the standard for sending a YPbPr signal became the D terminal connector instead of on RCA cables. I bring this up because the Framemeister uses a D-Terminal connector, and if you plan on using it with your RCA style component connectors, you will need an adapter.
And a note about BNC connectors. You'll find these on professional video equipment, so like PVMs and BVMs. They can carry a variety of signals, and the easiest way to think of them is professional RCA connectors. Though it does go a bit beyond that. For basic info purposes though that should work.
S-Video has it's own connector it is a little 4 pin din connector. This carries ground and the split video signal.
SCART and JP21. Both of these connectors can carry a wide array of signals. They are both 21 pin connectors, and in some ways think of them as the HDMI connector of the analog world. They do have different pin outs so DO NOT mix JP21 and SCART, pick one standard and stick with it for everything. While SCART and JP21 can carry RGB, just because a cable is SCART or JP21 doesn't mean it's an RGB cable. These could be composite video or s-video cables as well. One of the really nice things about these connector standards is that using one connector can connector your video lines, sync, and audio. You may be saying hey that kind of sounds like RF, but it is very different. In SCART and JP21 each of those signals is given their own line to ride down, vs all being combined into 1 wire. When buying SCART or JP21 cables, you want to make sure you know what you're buying. Like I said a SCART cable can be RGB, Composite Video, or S-Video, and it could be c-sync, sync on luma, or sync on composite.
SCART has kind of become the RGB standard in retro gaming. Its much easier to find switches, and other devices using SCART vs JP21.
Awhile back I made a chart showing the info for as many systems as I could and what was the best video signal they supported both stock and modded.
I need to include some updates to it and hopefully I can get to that in the next few days and then I'll replace this image, but it should give you a rough idea.
Other resources
Where can I get some awesome cables for my systems? Are there any recommended sellers?
You're in luck as there are a couple good places to order from online.
For RGB cables
https://www.retrogamingcables.co.uk/ A UK based seller, that does ship internationally
https://retro-access.com/ This is the US seller that used to be retro_console_accessories on ebay.
Component cables for older consoles
HDRetrovision makes a great line of cables that convert the RGB signal to component, YPbPr.
http://www.hdretrovision.com/
What about further material for learning about this.
There are some great resources out there for learning more about this stuff.
http://retrorgb.com/ Is a fantastic website with even more of this info, and Bob also does a weekly retro roundup on his youtube channel https://www.youtube.com/channel/UCLPIbBCKVH2uKGm5C4sOkew?&ab_channel=RetroRGB
You also have My Life in Gaming's youtube channel, and specifically their RGB Masterclass videos.
https://www.youtube.com/channel/UCpvtp7mH0Cdq8FQUxcjDq0Q?&ab_channel=MyLifeinGaming
A good video about Luma and Chroma from Displaced Gamers.
Intro to Chroma: From RGB to Component Video
How does Luma relate to Chroma? How does RGB relate to Y'PbPr? How do B'-Y' and R'-Y' form PbPr? Previous videos in this series - Analog Luma - A History and...
youtu.be
Last edited:
