Author Topic: PC Engine / Turbografx16 s-video mod  (Read 1794 times)

Duo_R

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Re: PC Engine / Turbografx16 s-video mod
« Reply #30 on: July 28, 2012, 09:15:32 AM »
Yeah that's pretty crazy, also not that long ago it was discovered some SNES units have built in component video, just needs to be wired to the jacks.


I find it funny how it took till now to just simply tap S-Video out of the system with just 2 parts. All these damn years, lol.

I remember saving up for region/S-video on my practically new US Duo and finally finding someone to do it (grahf) back in 2006. Glad I got 2 nice clean modded boards in there. Looks like manufactured quality parts instead of homemade pcb setups.
« Last Edit: July 28, 2012, 09:18:02 AM by Duo_R »
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NightWolve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #31 on: July 28, 2012, 04:18:32 PM »
Yeah that's pretty crazy, also not that long ago it was discovered some SNES units have built in component video, just needs to be wired to the jacks.


You sir, are awesome! Your mentioning of built-in component video peaked my interest which led me to search around for info about it, and in a couple of hours I was able to implement it on my SNES! It works wonderfully on my 32" CRT in my entertainment room, but I tried it on my modern 22" 720p HDMI flat panel (my computer's monitor) and it doesn't there. I know from thesteve and others that newer TVs demand a 480p YPbPr Component signal or they will reject it, so one would need a resolution doubler to make it work in that case. Anyhow, seeing it perform on my CRT was truly a blast. I tried Chrono Trigger, Super Bonk, F-Zero, Donkey Kong 3 and was quite amazed at the difference! I did have to turn the color level up, though. The S-Video output is very Chroma heavy compared to it, so that was one difference, but aside from that the component signal is mostly ready-to-go just by tapping the proper contact points (I think technically, as some experts are saying, the Blue and Red signals probably do need to be amped a bit, that or turning up the color level). I followed these:

http://www.nintendoage.com/forum/messageview.cfm?catid=22&threadid=71069
http://www.racketboy.com/forum/viewtopic.php?f=25&t=37716&start=90



Tapping the luma (Y) from the Multi-AV out (which is used for s-video) is the better point instead of the chip. Now I just need to buy a Component RCA mount to install on the case and solder the wiring for good. But anyway, yeah, as it is a 240p signal, it might not work in newer TV sets without a resolution doubler...

Oh yes, fair warning, I thought I broke my SNES at first. After you solder the wires to the board, you'll really need to put it back together for testing - the sound module has to make contact with the heat sink mold and what not. I tried to quickly test before putting it all back together but no game would load and I wound up burning out the fuse near the power switch f*cking around that way, so I had to solder a bypass wire unfortunately. Not good, but oh well. Also, newer revisions of the SNES board do not support Component - you can only do this if you got an early model with the S-ENC chip (mine is 1990) or that one in the image!
« Last Edit: March 26, 2013, 04:43:00 PM by NightWolve »

SNKNostalgia

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Re: PC Engine / Turbografx16 s-video mod
« Reply #32 on: July 28, 2012, 04:42:07 PM »
Yeah that's pretty crazy, also not that long ago it was discovered some SNES units have built in component video, just needs to be wired to the jacks.


I find it funny how it took till now to just simply tap S-Video out of the system with just 2 parts. All these damn years, lol.

I remember saving up for region/S-video on my practically new US Duo and finally finding someone to do it (grahf) back in 2006. Glad I got 2 nice clean modded boards in there. Looks like manufactured quality parts instead of homemade pcb setups.

Now, that just blew my mind. I thought there was some complicated mathmatical difference using a certain chip between red and blue to get component. It is setup to just work like that? Man.....

NightWolve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #33 on: July 28, 2012, 05:21:01 PM »
Now, that just blew my mind. I thought there was some complicated mathmatical difference using a certain chip between red and blue to get component. It is setup to just work like that? Man.....


If your SNES model has the S-ENC chip like you see in the first image, then yeah (Mine looks different because it's a 1990 early release model, just says S-ENC on it, no 'BA65942AF' and it's in a different location, very close to the Multi-AV out). The story is that they found the datasheet on that video encoder chip which shows you on page 6 that pin 24 is Blue-Y and pin 1 is Red-Y and Luma (Y) is the same Luma that was being outputted for the S-Video which SNES always had (though I hear some newer models were f*cked up and don't have it) hence you can tap it from the Multi-AV out. But yeah, newer revisions of the SNES removed this S-ENC apparently in favor of a S-RGB chip, so only raw RGB would be present in that case, thus you'd need the usual RGB->Component encoder... You still have the 240p problem not working with newer TVs of course.

Anyway, it's pretty cool, but it probably does need some amping. The color level has to be turned up, but other than that, it works beautifully on my 32" CRT. Compared to S-Video, (I would switch from s-video back to component during the testing) the message boxes had clear color, no fuzzy drawn sprites when there was movement, clearer drawn text, etc. Some fine tuning IS needed, but yeah, it might work well enough raw (as it does for me) with just soldering wires from the board to RCA jacks. I still have to research the fine tuning which I might as well do.

Screenshots from the guy whose mod images I used:

42" Plasma


35 inch CRT


So that's just tapping the signals raw like I just did today, no amps or anything. Color level of TV has to be turned up, maybe tint adjust too (according to him). That plasma looks beautiful!
« Last Edit: March 26, 2013, 04:44:15 PM by NightWolve »

thesteve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #34 on: July 28, 2012, 06:20:53 PM »
those outputs do need a buffer amp.
a simple transistor amp will do

NightWolve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #35 on: July 29, 2012, 01:59:11 PM »
Can you provide any more specific details, steve, that would like, you know, actually be helpful such as which transistor to buy and wiring methods, etc.? Some are saying resistors are needed too. Pretend you're talking to someone that doesn't have ANY of your engineering background. ;) I wanna put an order in for female RCA jacks so in wanting to do it properly, I can buy the stuff from the same place (assuming digikey/mouser will have all that I need).

thesteve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #36 on: July 29, 2012, 02:15:23 PM »

NightWolve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #37 on: July 29, 2012, 04:36:30 PM »
Hm, it seems there is a lot of confusion but I think understand better. One guy is reporting that if you have an actual BA6592F chip, you need the amps. I have the S-ENC chip with only 4 useless numbers on it, which, since it worked right away without anything, means I don't need the amps in my case (duh, other guys were reporting dark colors, mine worked pretty great)! Oh, and in the images I posted above, that chip is a S-ENC BA6594AF, slightly different number and it's working for the guy, which means it is already amplifying the signals for near proper usage strength, etc. Many board revisions and changes here, so that is the deal.

But, there was talk of needing 1k Ohm "pull-down" resistors. What do you make of this image ?



I think that might be more applicable in my case, though I dunno what the heck they're wanting to do to the luma signal. I am betting that if I tap the luma from the chip, it's going to work fine. Think I'm gonna do that now actually. But as you can see, it suggests a 1K Ohm resistor to ground for R-Y (Output) and B-Y (Output) pins. Moreover, with the Y/Luma (Output), pin 23, it wants a complex circuit using the luma input signal that enters the chip from pin 9! Why are they wanting that done, what difference would it cause and really, isn't the S-Video Luma the same as what an analog component signal uses? I kinda suspect it'd be more proper to do it like that and that maybe it'd make the whole component signal more compatible, aside from the 240p issue.

So, what I think is the deal is, technically, seems like the the Component video signal is supposed to be nearly ready for use by default without amps, no? I got a great picture (though a little low colorwise), and it seems those that found they had to use amps were just getting a dark one with another type of chip, though similar, etc. I dunno... whatever, it works pretty good in my case without anything and it's been somewhat interesting modernizing my good ole SNES, so not entirely a waste of time!

EDIT: Yeah, here's what he said (Ace): "I don't get it: it works on the S-ENC, but it doesn't work correctly on the actual BA6592F  ......  I was right. You need an amp for the real BA6592F. With no amp on the B-Y and R-Y outputs, you won't get any color. You also shouldn't take Luminance straight from the encoder, but rather pin 7 of the multi-A/V out as it too needs an amp which is already present on the motherboard."
« Last Edit: March 26, 2013, 04:45:25 PM by NightWolve »

thesteve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #38 on: July 29, 2012, 05:16:43 PM »
the 1K is the proper load for the chip
the transistor and resistors shown provides the 1K load to the chip, and keeps the 75Ohm load off it.
copy it for the other lines for better color

NightWolve

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Re: PC Engine / Turbografx16 s-video mod
« Reply #39 on: July 30, 2012, 03:14:38 PM »
The modding continues. Instead of buying female RCA jacks, I used a triple Component RCA mount from a DVD player that broke. Using a wood-boring drill bit, the SNES plastic was easy to handle. It worked out nicely:

http://i237.photobucket.com/albums/ff216/Sephiroth1975/General/IMG_1183.jpg

My 1990 first generation SNES PCB board near the 9239 S-ENC chip:

http://i237.photobucket.com/albums/ff216/Sephiroth1975/General/IMG_1180.jpg
« Last Edit: August 09, 2012, 12:18:26 AM by NightWolve »

Duo_R

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Re: PC Engine / Turbografx16 s-video mod
« Reply #40 on: July 31, 2012, 04:08:35 AM »
nice job Nightwolve, I have a jack exactly like that from an old broken DVD player. That turned out pretty nice!
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Duo_R

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Re: PC Engine / Turbografx16 s-video mod
« Reply #41 on: July 31, 2012, 07:15:55 AM »
I need to figure out where to mount a S-video connector on a CG unit, I suppose I could replace the 5 din connector with an 8 din and make two pins s-video (with a custom s-video cable). With the CD-unit that I have there really aren't that many options on locations to install. I assume s-video works fine in conjunction with CD-rom unit.
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Drakon

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Re: PC Engine / Turbografx16 s-video mod
« Reply #42 on: July 31, 2012, 07:23:57 AM »
no clue what cg means.  If the cd rom unit has you get video from where you get video without the cd rom then yes it should work fine with this mod.
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Duo_R

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Re: PC Engine / Turbografx16 s-video mod
« Reply #43 on: July 31, 2012, 07:28:36 AM »
CoreGrafx - it is like what you have except it has a 5 din plug instead of RF only like your White PC Engine.
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SNKNostalgia

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Re: PC Engine / Turbografx16 s-video mod
« Reply #44 on: August 02, 2012, 01:56:34 PM »
My SNES say S-RGB and BA6592F under that. So does that mean it still has component video with the same number?

If not, then what a shame. It doesn't have the known faded vertical bar in the middle of the screen like most SNES consoles.
« Last Edit: August 02, 2012, 02:01:35 PM by SNKNostalgia »