Outputting 240p RGB Scart from a modern Nvidia GPU

foreign [Music] hi guys so what I've got here is a little tutorial and it's how to get 240p out of a modern Nvidia graphics card so one where you're outputting either um DisplayPort or HDMI um and then taking that 240p and and outputting that via RGB scart um to go to a uh SD CRT television and doing this without introducing any lag um and so there's two kind of major issues with common ways of getting uh or maybe easy ways of getting a um an analog signal out of a computer or converting that Digital Signal into an analog signal and the first one is the introduction of lag and lag comes from when you've got a frame buffer so when you're scaling a video from a larger size down to a smaller one and so if we're outputting um you know we want our output 240p if we're not outputting a 240p from our source we're gonna have to scale that down and boxes like this you'll probably find videos online um that say oh you can use a box like this to connect a computer to a CRT television um this box in particular takes a VGA input so you can you know you can get VGA quite easily from converting HDMI to VGA we'll talk about that in a bit and then this one will output s video and composite this will actually take um any uh video signal any resolution and then scale it to to the output and this comes into our second problem is that often these devices output for Ati and not 240p so if we're playing a classic console such as a mega drive a snares uh Playstation One um often we'll want 240p out there that matches the original resolution so if you're emulating that on a computer um we want to get we want to get 240p not for Ati um another way of getting an analog video signal out of a out of computer is to use kind of an older graphics card so we'll see here we've got this port here you can get S video straight out of the graphics card here this is a um an NVIDIA GTX 285 um so I had and I was using to Output output um s video again without fiddling with the drivers typically that will output 4 ATI um another way of outputting 240p is to use um something I'm not actually very experienced with is that I've kind of seen is to use um I think CRT mu driver which typically I think uses um an older ATI graphics card or ATI um AMD at the HR AMD they become AMD right but um we're ATI but an older graphics card that will output VGA and then you can get you can get 240p out of that that is a completely valid way you can get 240p and not introduce lag and what I'll show you here is how to use a modern uh graphics card from Nvidia an output 240p from there so what we'll come on to we'll have a look at the Nvidia control panel the video control panel enables custom resolutions which is great but those custom resolutions are still coming out of either um DisplayPort or or HDMI um and so what we're going to have to do is take that 240p signal out via one of these digital forms um and convert that to a an analog signal but as I said we want to do this without introducing any lag so we want no boxes that are going to scale nothing's got that's got a frame buffer so the first thing is actually one of these converters I've got here so both of these are um digital to analog converters I'll just move the scart cable there and both of these will take in this case it's a this is the display port to VGA so in a second we'll talk about video signals and what we're doing to convert them so firstly we're doing this this conversion so our digital video signal and outputting an analog one bar an old television that runs in you know an SD television that runs in either you know can receive either for Ati or 240p over scar VGA is a typically a 31 kilohertz signal so we need to convert that signal um or it's uh not just that it's a 31 kilohertz signal but it has different components and we'll talk about the components of that video signal in a second so we need to convert this VGA signal into the RGB scart signal and same with the the HDMI adapter here so these sorts of DisplayPort or or HDMI to VGA adapters a pretty common place if you get one from a kind of reputable laptop brand these are often bundled with laptops because they um you know people might use them in in conference rooms and things like that if they want to project and particularly if that room has an old old projector um these do vary in quality but you can get ones that are um retain the picture in in terms of pretty high quality um and and typically these are are Lag less as well so next talking about the video signals so out of a you know standard uh VGA signal we've got the different components of the um that analog analog picture so we've got the three colors we've got RGB um and then we've got a sync signal as well there's two sync signals we have horizontal sync uh horizontal sync and and vertical sync um and so there are actually five signals that are separated out into separate separate cables um and this is why a VGA monitor can run much higher resolutions than for example you can get over over Scott because each of those signals is separate and running over different different cables and if they're shielded not interfering with each other and so you get a nice nice crisp picture and you can run VGA you know I've got a CRT PC monitor that runs 1600 by by 1200 much higher than a sort of 640 by 480 that you might get out of a out of a scart cable so we've got RGB HV um but if we want to Output a scar we need rgbs so the S stands for sync and that's a combined sync or kind of composite sync um where the H and the V are now combined into a single sync signal so there are four video signals coming out of the VGA coming out of the um scart cable going to the television so our first digital to analog conversion is happening via one of these little adapters then we need to combine that sync signal and that's where a box or box or little uh circuit board like this comes in so I actually bought this for my mister Mr fpga um to Output Scar from that um but I realize you can also use it for um converting that PC signal that VGA signal into a rgbs um to Output over Scott so this VGA to start board you can buy them for about 20 pounds this is a um designed by um Mike Chi of of retro tank um who's made then that design open source and you can buy you know you can either build it yourself or find people who will Who will sell this and I I bought this on eBay I think as it was about 20 pounds um what this does is it takes a VGA input you can also give it a um an audio input because scarc can carry both video and sound so we can give it video and sound um and it will combine those sync signals the H and the V into a composite um composite sync signal to Output over Scott so so the whole chain is basically we're going to Output 240p using the Nvidia control panel which we'll look at in a second um convert that digital signal I'll probably use this adapter this is the display port to VGA we're going to Output VGA so we've now got an analog signal but then we then convert that analog signal from rgbhv to rgbs and that rgbs then our TV can can recognize that and we can display a picture from PC a modern PC onto a um an old CRT CRT television so yeah let's now go to the Nvidia control panel and I'll show you how to how to configure that um and then hopefully we can demo demo working Okay so we've got everything hooked up and you'll see my television uh there um it's uh bang Olufsen um CRT television and at the moment you can see it's just displaying a cardboard picture because it's not receiving a signal um that it can display so I've got the cable connected up so we've got the um DisplayPort to VGA connected to the my Nvidia graphics card I've got a um GTX uh 1060. um but you know any any kind of later uh you know currently supported Nvidia graphics card I think will work fine with this method so we've gone DisplayPort to VGA via the adapter I've then got a VGA cable that's kind of running um to the left of me and that's then running to the VGA to start box and that VGA Scott box needs a micro USB power supply um which I've got hooked up and then um the outputs Scar and that goes to the television um we've seen the uh Nvidia control panel that we've got got open here I've got three monitors connected the one here is a the one I'm showing you which is my um VGA CRT PC monitor got a flat panel here and then this one here is our our television at the moment you see it's been sent 1024 by by 768 a resolution that the television can't display so we're going to go to customize here um and what we're going to do is add a custom resolution first we're going to enable resolutions not supported by the display because at the moment the computer doesn't unreally understand what just what resolutions um our television can can display and then we're going to go create custom resolution so here there's a few settings you can really configure this quite significantly and we're going to Output just basic 240p so we're going to change it for to the horizontal to 320 and the vertical to 240. I've seen some people when they're doing this um talk about kind of super resolution so having much higher horizontal horizontal resolution um my television doesn't seem to want to handle that or maybe I'm not configuring it quite right um but we're just going to give it standard 240b 320 by 240. um the sort of this timing bit I've had the most success when I've changed it to um CVT reduce blank and then and then stuck it on and kind of manual so I can then edit these so the any of these presets you set to kind of changes the numbers um there's things like this front front porch um which I don't fully understand what those numbers mean um but we can get it to you know I've been able to get it to work the total pixels here um is something to bear in bear in mind this is the total number of pixels they're being sent to the center that um display and so you can change this um fortunately with this television here I can control things in the service menu reasonably reasonably well but hopefully this this will now this will now work so if we go test so that's going test and you'll see um behind me not that we can see very well because we're capturing a CRT um scrt via the via the webcam um I got a message come up say you know are you sure you want to use this resolution I went okay because we've just done the test we've not set it but we saw that we did get a picture on the TV there and it was just showing the the desktop so we'll hit OK and now we see this custom resolution appear here um a a note what I think is possibly a slight bug with the Nvidia control panel when I kind of you know we can select this and we can change to it if you disconnect the display and reconnect it sometimes this custom resolution doesn't always appear I found if you go to customize and you just edit it and you change for example you know one pixel on the front porch or something like that um and then test it it will then reappear in this in this menu and it becomes become selectables it seemed a little bit fiddly so we're now going to go to apply um and you can just about see there on the television um that we've got we've got windows and so here's your desktop configuration has changed would you like to keep these changes yes because it looks like it's working um and so now what I'm going to do is um boot up uh a an indie game um and then we can have a look and see that we're getting nice proper 240p uh out of this computer okay so here's the TV and you'll see we've got the 240p output here I've um fired up docular here from locomolito um and and yeah that is it so if I zoom in if I go a bit closer we'll see that the yeah this is proper 240p it's not it's not um not 480i we haven't got any sort of flicker on the on the on the text here other than my television having seen to bit a bit of a bounce at the top of the screen there and the uh geometry is probably not as good as it could be but such is life with uh these old TVs um and and to be honest the camera the camera doesn't do this do this Justice in in um in person it looks really sharp and and and nice on the on the lcrt here um and so for particularly modern uh kind of Indie indie games that basically are designed as if they were playing in 240p um playing on on old TV like this or you know something like an arcade monitor I I think that's a great way to play these these old classics or the modern takes on the old classics um so yeah I hope this has been uh useful to people um let me know in the comments what you think let me know if there's anything I could be doing this any better um but yeah I I think it's useful um and I'm I'm intending to to play more games uh on my old TV straight out of my PC so yeah you guys stay safe I'll catch you soon see you then bye [Music]

Channel: LondonRetroVideoGames

Views: 12,926

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Id: GSBxHvrR7sw

Length: 15min 49sec (949 seconds)

Published: Tue Dec 13 2022