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Hi Folks,

I'm trying to hook up my GameGear to my TV, and I've heard it is indeed possible. Here's what I know so far:

1) Pin 36 of the TMS9918A VCD chip is labeled COMVID. Hmmmm.

2) Pin 43 of the Cart slot is labeled TV and I think only refers to the TV tuner cart.

3) Pins 44 and 45 are labeled respectively TVSNDR and TVSNDL,and they are the TV's right channel and the TV's left channel (left and right channels for video??!!! I thought only audio did that--can anyone clear this up?).

4) Years ago in issue #8 of Electronic Gaming Monthly, there was a pic of the GG connected to a TV. They had the (facing the back) right battery compartment filled with a little circuit board. I remember they mentioned that there was a contact they couldn't tell you about that gave video output. I think I lost this issue 9 years ago.

5) I tried tapping the pins on 2) and 3) above but it didn't work (yes, I made sure that I grounded the ummmm...ground first). I didn't think it would work, but I gave it a shot anyway.

The only thing I didn't try is 1). I just found that bit of info 2 minutes ago. Anyone have any ideas? I was surprised at the astounding amount of info out there on the GameGear, but this little shred of info has been impossible for me to find. Hope you guys can help. I'd be most grateful!!

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> 4) Years ago in issue #8 of Electronic Gaming Monthly, there was a pic of the GG connected to a TV. They had the (facing the back) right battery compartment filled with a little circuit board. I remember they mentioned that there was a contact they couldn't tell you about that gave video output. I think I lost this issue 9 years ago.

This is what the Game Gear looks like:

(I bought this Game Gear from someone working at Electronics Arts)

The board doesn't look so simple to me :(

Hmmm. I always figured that since the GG was a bit of a suped up Master System, then there should be an output on it somewhere. Also, the LCD runs on typical NTSC standards, unlike a Gameboy, which is probably FAR from simple to connect to a TV.

Nice pic though! How much did you snag that system for?

I wonder if that thing is just some kind of RF converter or something. Does it have RCA outputs?

Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-)

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> This is what the Game Gear looks like:
> (I bought this Game Gear from someone working at Electronics Arts)

> The board doesn't look so simple to me :(

Gee, you've got one of these? That's got to be one of the holiest grails of GG hacking. I'd only heard rumours that this exists before. Have you posted information on it somewhere? Even if the ICs aren't obtainable it'd still be nice to get an idea of how it's done.

And hey Bob, what's that you say about the LCD using NTSC signals? Any more info on this?

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> Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-)

Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models.

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> Nice pic though! How much did you snag that system for?

Theorically 50$ (quite cheap) but the ok went away with 150$ actually.
Oh well.

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> Gee, you've got one of these? That's got to be one of the holiest grails of GG hacking.

See the product number ;-)
105, there wasn't much of them I guess.

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> I'd only heard rumours that this exists before.

I was originally provided to developers.

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> Have you posted information on it somewhere? Even if the ICs aren't obtainable it'd still be nice to get an idea of how it's done.

I'll see what I can get out of it. But the board you see is tighty attached on the behind so it cannot be manipulated easily.

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> Hi Folks,

> I'm trying to hook up my GameGear to my TV, and I've heard it is indeed possible. Here's what I know so far:

> 1) Pin 36 of the TMS9918A VCD chip is labeled COMVID. Hmmmm.

The Game Gear doesn't have a TMS9918A chip. (Nor does the SMS.)The GG's VDP (integrated into one of the large VLSI ICs) is based on the TMS9918A and offers backwards compatibility with the SMS graphics mode, but that's all.

There's certainly no composite output available from any pin on the GG's main IC(s). Even the SMS doesn't have this (a Sony CXA1145 encoder is used to generate composite from RGB inside the SMS). There *may* be RGB outputs and sync signals, but I very much doubt it.

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> 2) Pin 43 of the Cart slot is labeled TV and I think only refers to the TV tuner cart.

Yes (it switches between GG mode and "TV mode", where certain pins of the cart slot function as inputs to the LCD display).

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> 3) Pins 44 and 45 are labeled respectively TVSNDR and TVSNDL,and they are the TV's right channel and the TV's left channel (left and right channels for video??!!! I thought only audio did that--can anyone clear this up?).

Yep, they're audio inputs (left and right channels, for stereo sound) and are used by the TV tuner.

I think it's likely to be far from trivial to connect your GG to a TV, unfortunately.

Mike

And hey Bob, what's that you say about the LCD using NTSC signals? Any more info on this?

Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they converted the SMS architechture to a GG? This would ring especially true since you can use a tv tuner cart with it. I guess the same would go for a turboexpress...

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> > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-)

> Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models.

Hmmmm. Perhaps by using spare SMS parts one could relatively easily implement this then. Perhaps it really is just an (modified?) RF box?!

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> Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I

Oh, so there aren't actually NTSC signals running around in there?

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> believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they converted the SMS architechture to a GG? This would ring

Yeah, it would muck up the timing in MS games and cheap GG conversions. I don't want to try and think what happens in 50Hz countries, isn't GG the same anywhere? Meaning that a 50Hz TV tuner would be in a little trouble.

Incidently, did anyone figure out how the TV tuner gets its signal in? Surely it's not limited to 16 colors? Even changing the palette every scanline sounds a bit messy.

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I

> Oh, so there aren't actually NTSC signals running around in there?

Ummm as far as I know there are.

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> > believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they converted the SMS architechture to a GG? This would ring

> Yeah, it would muck up the timing in MS games and cheap GG conversions. I don't want to try and think what happens in 50Hz countries, isn't GG the same anywhere? Meaning that a 50Hz TV tuner would be in a little trouble.

I think the Euro GG are actually PAL, as is the TV tuner (There was a PAL TV tuner, right? Pretty sure there was...think I read about that).

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> Incidently, did anyone figure out how the TV tuner gets its signal in? Surely it's not limited to 16 colors? Even changing the palette every scanline sounds a bit messy.

When the tuner is in, it doesn't use the GG VCD. It just uses the GG's display and the tuner card, along with the GG's power, so color restrictions don't apply....it just uses the screen as a NTSC monitor, afaik.

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> I think the Euro GG are actually PAL,

European Game Gear runs at 60 hz.
I clearly remember that since when I first tried a Master Gear ten years ago (games were running faster) and I can confirm it now.

But there's a TV Tuner that works everywhere in Europe *EXCEPT FRANCE* (damn) because we're using Secam.

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> Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The

way I see it, why would they change the format when they

Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input?

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input?

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> > > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-)

> > Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models.

>
> Hmmmm. Perhaps by using spare SMS parts one could relatively easily implement this then. Perhaps it really is just an (modified?) RF box?!

I have no idea what is an RF box, unfortunately: never saw one since we don't use them in France.
May I be able to help bringing closer pictures of the board front ?

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

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> > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> way I see it, why would they change the format when they

> Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

... someone's so excited, they hit the Submit button too much :o)

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> I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games.

From my experience with flicking between NTSC and PAL standards on my TV card, if it was outputting PAL there'd be no picture.

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> Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG.

They're all 60Hz (or 59.94, whatever). There's no need for 50Hz systems when there's no 50Hz output requirement. Not that Sony realised this for the PS2... Sega had more sense with the DC.

There are a few games which require PAL display timing, and I think they choke on a Master Gear, the same as when run on an emulator simulating the wrong number of display lines (I don't know the numbers offhand). The vast majority of games never had a proper PAL conversion.

Maxim

Hey Guys,

Really sorry about the repeat...dunno what the hell happenned...the submit button wasn't working...or so I thought.

1000 pardons :-)

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> > > > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-)

> > > Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models.

> >
> > Hmmmm. Perhaps by using spare SMS parts one could relatively easily implement this then. Perhaps it really is just an (modified?) RF box?!

> I have no idea what is an RF box, unfortunately: never saw one since we don't use them in France.

> May I be able to help bringing closer pictures of the board front ?

That would be great! I bet we's all like to see where those wires lead to! An RF box generally converts the Composite to older tvs that take an RF signal...stands for radio frequency...it's an analog standard of lower picture quality that earlier tvs understand.

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> > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The
> > way I see it, why would they change the format when they

> > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

> You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

I traced these 4 capacitors to pins 36-39 and 55-58 of the LCD screen. C22 goes to pins 36 and 55. C23 goes to 37 and 56, etc. I haven't traced them backwards yet, but I will.

My dad is a TV repairman, and he believes that there is no color sync, judging from the discription of the pic in this thread (he didn't actually see it), hence the garbled screen. I tried tapping these capacitors on my TV and I got some very fuzzy and jittery black and white screens to come up. I had to adjust the vertical to stabilize it as much as I could, but it was still pretty distorted, but I could DEFINITELY make out what I was seeing....sometimes. Sometimes the picture was a bit diagonal, sometimes it would float from the left of the screen to the right and scroll over rapidly, but it was there.

This is a great start...I think we might be on a roll!

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> you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of

That picture was with it connected to the ground in the GG, but it sort of worked just leaving it hanging.

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> the probs you mention might be due to the PAL system being

I tried it with my TV card set to PAL, NTSC and even SECAM. Only NTSC was reasonable, the others having fields missing, wrong size, etc, but I suppose it depends how strictly your TV adheres to the standards. Actual analog TVs might be more limited, I don't have an NTSC one though. What standard country do you live in?

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> My dad is a TV repairman, and he believes that there is no color sync, judging from the discription of the pic in this

That sounds pretty likely, especially when you notice that what's supposed to be black is black, and what's supposed to be differently colored is different. I can't pretend to know if missing color sync explains why white stays white. It comes out quite cleanly if I turn down the color on my TV. Filtering out the color subcarrier would probably be better though.

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> seeing....sometimes. Sometimes the picture was a bit diagonal, sometimes it would float from the left of the screen to the right and scroll over rapidly, but it was there.

Possibly there's no vert/horiz sync pulses either, I suspect my TV card is cleverly guessing where it thinks they should be, the way some other images come out suggests this quite strongly.

Do you have a scope? If not, when I find the time I'll try and see what's actually going on, and check other pins too, parts of the video signal might be seperate and in that case probably out of spec too.

By the way, in MS mode, you get a bigger picture, same pixel size. But that can be changed to what the LCD shows depending on how you use the MS/GG input. It's really odd.

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> Really sorry about the repeat...dunno what the hell happenned...the submit button wasn't working...or so I thought.

I've noticed that too.

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> > you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of

> That picture was with it connected to the ground in the GG, but it sort of worked just leaving it hanging.

I tried it on my TV with an RF box and it came in like crap. I tried it on a good TV with composite, and I actually got some clean pictures sometimes (still black and white). Even onthis TV though, they were still jittery. I let the game run through the demo and the title screen (Sonic Chaos), and it usually was stable at the title screen, sometimes stable at the demo, and usually screwed up where Sonic and Tails run after Eggman/Robotnik. Other times, it did whatever the hell it wanted. It may be just coincidence, but I seemed to get a better pic out of C23...

By the way, the bottom pins of these 4 Capacitors are ground, but they also lead to many other places (which all seem to be common to the four of them....). I couldn't get a signal at all unless I had a the ground grounded.

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> > the probs you mention might be due to the PAL system being

> I tried it with my TV card set to PAL, NTSC and even SECAM. Only NTSC was reasonable, the others having fields missing, wrong size, etc, but I suppose it depends how strictly your TV adheres to the standards. Actual analog TVs might be more limited, I don't have an NTSC one though. What standard country do you live in?

I live in USA...NTSC.

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> > My dad is a TV repairman, and he believes that there is no color sync, judging from the discription of the pic in this

> That sounds pretty likely, especially when you notice that what's supposed to be black is black, and what's supposed to be differently colored is different. I can't pretend to know if missing color sync explains why white stays white. It comes out quite cleanly if I turn down the color on my TV. Filtering out the color subcarrier would probably be better though.

It seems there is another problem other than the color sync though. Even if the colors were correct, the signal is still wacked-out. Sometimes it just doesn't display what it's supposed to, but other scenes are correct. It's usually the same screens that screw up and the same scenes that display relativley stabily.

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> > seeing....sometimes. Sometimes the picture was a bit diagonal, sometimes it would float from the left of the screen to the right and scroll over rapidly, but it was there.

> Possibly there's no vert/horiz sync pulses either, I suspect my TV card is cleverly guessing where it thinks they should be, the way some other images come out suggests this quite strongly.

Maybe, but like I said, some scenes were correct (but black and white).

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> Do you have a scope? If not, when I find the time I'll try and see what's actually going on, and check other pins too, parts of the video signal might be seperate and in that case probably out of spec too.

I do have a scope somewhere, but I wouldn't recognize the signals I see :-) I wish I could hookit to my computer, because at least the I could offer screen grabs of the signals.

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> By the way, in MS mode, you get a bigger picture, same pixel size. But that can be changed to what the LCD shows depending on how you use the MS/GG input. It's really odd.

Hmm.. not sure If I understand what you mean here. Strange stuff indeed!

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> clean pictures sometimes (still black and white). Even onthis

This could fit in with the no color sync theory as the TV might not find it and assume it's a black and white signal which isn't meant to have color sync anyway.

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> stable at the title screen, sometimes stable at the demo, and usually screwed up where Sonic and Tails run after Eggman/Robotnik. Other times, it did whatever the hell it

Sounds much like Sonic 2 did for me. This picture is supposed to be round, but it always comes out like that. My guess is that the TV may be mistaking the right hand edge of the circle with an h-sync pulse and starting the next line there.

signals I see :-) I wish I could hookit to my computer, because at least the I could offer screen grabs of the signals.

No video capture card? No digital camera? And you say you live in America? Something doesn't quite add up :)

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> > By the way, in MS mode, you get a bigger picture, same pixel size. But that can be changed to what the LCD shows depending on how you use the MS/GG input. It's really odd.

> Hmm.. not sure If I understand what you mean here. Strange stuff indeed!

This is the MS game Hang-On running in MS mode. That's the full TV screen. And yep, the track is supposed to be curved like that.

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> > clean pictures sometimes (still black and white). Even onthis

> This could fit in with the no color sync theory as the TV might not find it and assume it's a black and white signal which isn't meant to have color sync anyway.

> > stable at the title screen, sometimes stable at the demo, and usually screwed up where Sonic and Tails run after Eggman/Robotnik. Other times, it did whatever the hell it

> Sounds much like Sonic 2 did for me. This picture is supposed to be round, but it always comes out like that. My guess is that the TV may be mistaking the right hand edge of the circle with an h-sync pulse and starting the next line there.

> signals I see :-) I wish I could hookit to my computer, because at least the I could offer screen grabs of the signals.

> No video capture card? No digital camera? And you say you live in America? Something doesn't quite add up :)

Heh heh. That's because I spent all my money on video games! Actually, I DO have a digital camera attachment for my Palm IIIc. I will try to get some screen pics (glad you reminded me of that!). Don't worry, I generally only use my Palm for videogames, heh heh (plus I won it at work, so no money spenton things other than videogames:-). If you want a real laugh, would you believe my home system is a P166 w/40mb ram!?

I think your theory on the H-sync pulse is probably right. I hadn't thought of that. Still, I'm not sure that it explains why some scenes are displayed differently each time, but some are always the same.

If we do find a C-sync output, how do we tie it in with the composite? I'm pretty sure rgb and SCart tvs do this (only on seperate pins), but I've never used an scart or rgb tv...so I'm not sure how the pinswould tie together to make one composite output. Do we just tie them together in a composite signal, or must they be somehow seperated like scart/rgb?

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>>> I have no idea what is an RF box, unfortunately: never saw one since we don't use them in France.
>> May I be able to help bringing closer pictures of the board front ?
> That would be great! I bet we's all like to see where those wires lead to! An RF box generally converts the Composite to older tvs that take an RF signal...stands for radio frequency...it's an analog standard of lower picture quality that earlier tvs understand.

Then RF is the antenna plug, right ?
It doesn't output RF signal, for sure.

I'll give a look to the system later today.

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> Then RF is the antenna plug, right ?

RF = Radio Frequency, ie. same as antenna signals.

Maxim

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> > Then RF is the antenna plug, right ?

> RF = Radio Frequency, ie. same as antenna signals.

> Maxim

All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D

~unfnknbvbl

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> > > Then RF is the antenna plug, right ?

> > RF = Radio Frequency, ie. same as antenna signals.

> > Maxim

> All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D

> ~unfnknbvbl

Some tv's don't allow that. Your's is probably newer, so it new what you were doing and translated the signal. SOme tv's only will accept the antenna signal.

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> If we do find a C-sync output, how do we tie it in with the composite? I'm pretty sure rgb and SCart tvs do this (only on seperate pins), but I've never used an scart or rgb tv...so I'm not sure how the pinswould tie together to make one composite output. Do we just tie them together in a composite signal, or must they be somehow seperated like scart/rgb?

Well, I couldn't get my Palm digital camera attachment to take any good pictures because the room my tv is in has awful lighting. However, I do have some news to report. I'm pretty sure that 3 out of the 4 capacitors is R, G, and B. The reason is that I would tap all four of them at once and certain "color" shades went away (remember, they are all black and white) as I took each contact away. I'm not exactly sure what the fourth is, as it gives a video signal too, I just don't know exactly what it's doing that' different than the others.

I tapped every pin on the LCD and nothing seemingly significant happenned except for the LCD pins tied directly to the 4 capacitors.

Also, I have more evidence to reinforce the theory that it is truly the color sync we are missing. Whenever the background is black, or if there is a great majority of black on the screen, the picture starts to roll rapidly like in the Sonic 2 pic in this thread. If the screen is very bright, or white, the picture is nearly perfect exept there's no color, of course. This type of occurence was apparent in Sonic 2, Sonic Chaos, Devilish, and in Cosmic Spacehead.

So, like I said earlier, I wouldn't know a color sync signal if it bit me in the behind, so if we find the pin that gives csync, what do we do with it to make it work in a composite signal?

Quote

> > > > Then RF is the antenna plug, right ?

> > > RF = Radio Frequency, ie. same as antenna signals.

> > > Maxim

> > All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D

> > ~unfnknbvbl

> Some tv's don't allow that. Your's is probably newer, so it new what you were doing and translated the signal. SOme tv's only will accept the antenna signal.

Hmm... well, it's worked on all the TVs I've tried it on.. even a crappy old TV that had a rooted picture tube that you could barely see anything on, which was so old that it had wood panelling on the sides... can't get much older than that..

But then, it may because of the PAL signal...

~unfnknblvbl

Quote

> > > > > Then RF is the antenna plug, right ?

> > > > RF = Radio Frequency, ie. same as antenna signals.

> > > > Maxim

> > > All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D

> > > ~unfnknbvbl

Hmmm. Strange. Can't hook my systems up to any of my old tv's w/o the Rf modulator box

Quote

> > Some tv's don't allow that. Your's is probably newer, so it new what you were doing and translated the signal. SOme tv's only will accept the antenna signal.

>
> Hmm... well, it's worked on all the TVs I've tried it on.. even a crappy old TV that had a rooted picture tube that you could barely see anything on, which was so old that it had wood panelling on the sides... can't get much older than that..

> But then, it may because of the PAL signal...

> ~unfnknblvbl

I had a brief look on a scope today but I was a bit pressed for time so didn't get a lot done. I only paid attention to C25, the other three seem similar.

It's 4.8V peak-peak compared to 1V for NTSC or PAL, but the 75ohm input on a TV would no doubt reduce that significantly, didn't check how much though.

It doesn't sync pulses, at least not standard ones, apparently no color burst(sync) either. Where there's picture data it goes all the way between 0 and 4.8V. Between lines and I think also black regions are 0V. A real signal should only go to 0 during sync pulses with black being about 1/4 of the maximum voltage.

The line frequency is 15.71kHz +/- 0.2kHz, which more or less matches NTSC's 15.734264 kHz, and is way off PAL's 15.625kHz.

The picture in this message shows what looks like two fields (a field being one half of the interlaced frame - every second line), grey parts are where it's shooting up and down too fast to see. But the width implies a refresh rate of about 125Hz compared to 60Hz for NTSC. It could be 2*60Hz, but I don't know what that would mean. Either way I'm suprised our TVs handle it as well as they do.

I'll try to have another go in a few days and hopefully get some better data and check other parts of the circuit for possible sync pulses.

Quote

> If we do find a C-sync output, how do we tie it in with the composite? I'm pretty sure rgb and SCart tvs do this (only on seperate pins), but I've never used an scart or rgb tv...so I'm not sure how the pinswould tie together to make one composite output. Do we just tie them together in a composite signal, or

I don't know how it's supposed to be done, but for a cheap answer you can probably just do that if you're generating one of the signals, maybe with some series resistors too. Shouldn't be a major problem.

Aar yaah, here we go again.

I made a mistake with the 125Hz scan rate in my last post, it turns out it really is NTSC's ~60Hz after all, which is most excellent.

To convert the C25 signal into NTSC it would need horozontal sync, vertical sync and color burst added, and possibly be reduced in amplitude slightly, but that's trivial.

Horozontal sync pulses could easily be generated from point E (see below) to keep every line in the correct horozontal position on the screen. With just this it would probably be fairly usable. I'll try to work on a circuit for it.

I don't know about vertical sync, but that's not so important, could be obtained from C25 with a bit of cleverness.

Don't know about color burst either, that is assuming it even has the correct frequency and format of the color subcarrier. It's possible that it already has this, but I just didn't find it, and a TV wouldn't find it with no h-sync, it's only a couple of us wide, just before the image data on each line.

Line frequency fH = 15.700kHz +/- 0.002kHz. NTSC is 15.734kHz. Not sure how I got the dubious value in my previous post, but it was using a different frequency counter. Don't trust the uncertainty, but even if it is correct I doubt any TVs will have a problem with the slightly different frequency. In case you don't know what I'm on about, the line frequency is the number of horozontal lines per second, or to put it another way, the inverse of the time taken to scan one line across the screen.

Here are the signals I've measured(all relative to ground) in case they're any use, beware of the ASCII art:

Non grounded pin of C25 where the actual video data is:

Lines
__4.8V open cct, 1V with 75ohm load.
| ||| || | ||
||||||||| |||||
|||||||||| |||||
___||||||||||___||||| __0V

|<--- fH --->|
|<------>| Image data, width varies.

Fields
__4.8V open cct, 1V with 75ohm load.
|||||| |||
|||||||||| |||||
|||||||||| |||||
___||||||||||___||||| __0V

|<---------->| 61Hz +/- 2Hz.
|<------>| Image data, width varies.

Point E:

___ ___ __4.8V +/- 0.4V
| | |
| | |
|___| |___ __0V

|<-fH ->|

Rising edges are synchronized with the center of the space between lines.

This is another signal that pops up in many different places and may possibly be relevent, but I don't have any idea how:

Point B:
___ ______________ ___ __5.2V +/- 0.4V
| | | | __3.6V +/- 0.4V
|||| ||||
|||| ||||
|||| |||| __1.0V +/- 0.4V

__0V

|<----- fH ------>|
-->| |<-- 10us +/- 2us
-->||<---- 7.7MHz +/- 0.6MHz

The center of each 7.7MHz burst is synchronized with the center of the image data in a line.

Where are points B and E?

Looking from the back of the unit, immediatly below R22 are three holes in a diagonal straight line, I call the left most one point E.

Below and to the left of these is a diagonal row of four holes, point B is the second one from the left.

Brief description of what a video signal looks like.

Quote

> sure that 3 out of the 4 capacitors is R, G, and B. The reason is that I would tap all four of them at once and certain "color" shades went away (remember, they are all black and white) as I took each contact away. I'm not exactly sure what the fourth is, as it gives a video signal too, I just don't know exactly what it's doing that' different than the others.

Ah, that'd be nice, is the fourth C25? That's the one that looks different to me. I'm not too sure how you're saying you set it up, but I suppose you'd need a TV with RGB inputs to check it properly, maybe a VGA monitor would work, but that sounds pretty iffy.

Quote

> So, like I said earlier, I wouldn't know a color sync signal if it bit me in the behind, so if we find the pin that gives csync, what do we do with it to make it work in a composite signal?

From what I've read it's about 10 cycles of 3.58Mhz at the beginning of each scanline.

How to connect it would depend. One way might be to pass it through an amplifier to reduce the output impedance, then connect that straight into the main video line so it can just force whatever else is there into submission. Or maybe do without the amp - knowing how tolerant TVs are of out-of-spec signals pretty much anything could work. Though it might also need phase shifting, since the phase of the color sync is quite critical.

I believe the GG's (and SMS's) CPU clock frequency is exactly the same as the NTSC color subcarrier's which means if we can just find a clock line, that may do as the beginning of a color sync.

Quote

> > sure that 3 out of the 4 capacitors is R, G, and B. The reason is that I would tap all four of them at once and certain "color" shades went away (remember, they are all black and white) as I took each contact away. I'm not exactly sure what the fourth is, as it gives a video signal too, I just don't know exactly what it's doing that' different than the others.

> Ah, that'd be nice, is the fourth C25? That's the one that looks different to me. I'm not too sure how you're saying you set it up, but I suppose you'd need a TV with RGB inputs to check it properly, maybe a VGA monitor would work, but that sounds pretty iffy.

> > So, like I said earlier, I wouldn't know a color sync signal if it bit me in the behind, so if we find the pin that gives csync, what do we do with it to make it work in a composite signal?

> From what I've read it's about 10 cycles of 3.58Mhz at the beginning of each scanline.

> How to connect it would depend. One way might be to pass it through an amplifier to reduce the output impedance, then connect that straight into the main video line so it can just force whatever else is there into submission. Or maybe do without the amp - knowing how tolerant TVs are of out-of-spec signals pretty much anything could work. Though it might also need phase shifting, since the phase of the color sync is quite critical.

> I believe the GG's (and SMS's) CPU clock frequency is exactly the same as the NTSC color subcarrier's which means if we can just find a clock line, that may do as the beginning of a color sync.

If that is the case (which I would have never thought of), what about the pins of the clock case itself? The little metal-coated can thing next to the lcd would be a direct clock line, I think. Aren't those things made of a quartz crystal or something? I think I tried connecting this with one of the output capacitors and it didn't give any csync...maybe you guys might find otherwise.

Quote

> If that is the case (which I would have never thought of), what about the pins of the clock case itself? The little metal-coated can thing next to the lcd would be a direct clock line, I

I suppose so, don't know much about crystals. But that'll be a continuous oscilation, it'd have to be switched on briefly just when it's needed, might need the waveform modified too, who knows. Though that all sounds doable. What I'm worried about is that it might end up very complicated (ie expensive) while there may be a much easier way which Sega's one uses. I wish we knew where that PCB of Zoop's is connected to, or anything else about it, that'd be a huge plus.

Quote

> > If that is the case (which I would have never thought of), what about the pins of the clock case itself? The little metal-coated can thing next to the lcd would be a direct clock line, I

> I suppose so, don't know much about crystals. But that'll be a continuous oscilation, it'd have to be switched on briefly just when it's needed, might need the waveform modified too, who knows. Though that all sounds doable. What I'm worried about is that it might end up very complicated (ie expensive) while there may be a much easier way which Sega's one uses. I wish we knew where that PCB of Zoop's is connected to, or anything else about it, that'd be a huge plus.

Yeah, he mentioned he'd try to get some scans of it soon. That would be really good. I did check out that clock chip (that little metal box is the clock, as it turns out). There is a row of 1 capacitor then two Resistors, and below it is one more capacitor to the right of the clock. See the wonderful ASCII art below:

______
| C | C? R? R24
| L |
| O |
| C | C??
| K |
|_____|

These ?s are because the number of these are obscured by the LCD backlight leads. Anyway, the clock has two pins on the underside of the board. The one that is closest to the bottom of the board leads to the top and bottom of R? and the top of R24. The top lead of the clock leads to the top of C? and the bottom of R24. Tying either of these to any of C 22-25 did nothing but short out the GG.

That would be really good. I did check out that clock chip (that little metal box is the clock, as it turns out). There is a row of 1 capacitor then two Resistors, and below it is one more capacitor to the right of the clock. See the wonderful ASCII art below:

Quote

> ______
> | C | C? R? R24
> | L |
> | O |
> | C | C??
> | K |
> |_____|

OK, so the ascii art didn't turn out as planned. Just move the |s over to line up with the right edge of the _s and it should be clearer.

Quote

> These ?s are because the number of these are obscured by the LCD backlight leads. Anyway, the clock has two pins on the underside of the board. The one that is closest to the bottom of the board leads to the top and bottom of R? and the top of R24. The top lead of the clock leads to the top of C? and the bottom of R24. Tying either of these to any of C 22-25 did nothing but short out the GG.

Quote

> Aar yaah, here we go again.

> Horozontal sync pulses could easily be generated from point E (see below) to keep every line in the correct horozontal position on the screen. With just this it would probably be fairly usable. I'll try to work on a circuit for it.

Point E turns out to be a lead off of C20. Why woud this make a hsync? It didn't do anything when I tied it C22-25, btw.

Quote

> I don't know about vertical sync, but that's not so important, could be obtained from C25 with a bit of cleverness.

I think if we can get the v or h sync, maybe the other would follow (at least on smarter tv's...who knows). Maybe not.

Quote

> Below and to the left of these is a diagonal row of four holes, point B is the second one from the left.

This leads to the bottom of R19.

Time to add some real confusion to the mix.

I got my Master Gear converter today (I won it in an ebay auction that also included a Master Link cable to use a Second player in MS games!).

I tried connecting Leads c22-25 to my tv and got some very strange results. It did fill the screen as it's supposed to, but I actually had it in color! The wrong colors, though. I got the best signal of C25. C23 was good too, but the best signal was with C23 and C25 together. C22 and 24 did nothing much. I think 22 made the screen roll vertically and made it very dark at that.

Anyway, I was playing Alex Kidd IMW and the sky was green, and alex had black hair. When I added C23 to this, alex's hair seemed to be the right color and the sky was still green, only a little more yellow. The weird thing is, Red, Green, and Blue did appear on onscreen objects, but it seemed they weren't in the right places. Even though it had some items right (alex's colors).

I Don't know what to make of this. I really didn't expect any color out of this. I hope this doesn't set us back....

Author	Message
Rob Guest	Gamegear Composite output? Posted: Fri May 11, 2001 9:45 pm
Rob Guest	Hi Folks, I'm trying to hook up my GameGear to my TV, and I've heard it is indeed possible. Here's what I know so far: 1) Pin 36 of the TMS9918A VCD chip is labeled COMVID. Hmmmm. 2) Pin 43 of the Cart slot is labeled TV and I think only refers to the TV tuner cart. 3) Pins 44 and 45 are labeled respectively TVSNDR and TVSNDL,and they are the TV's right channel and the TV's left channel (left and right channels for video??!!! I thought only audio did that--can anyone clear this up?). 4) Years ago in issue #8 of Electronic Gaming Monthly, there was a pic of the GG connected to a TV. They had the (facing the back) right battery compartment filled with a little circuit board. I remember they mentioned that there was a contact they couldn't tell you about that gave video output. I think I lost this issue 9 years ago. 5) I tried tapping the pins on 2) and 3) above but it didn't work (yes, I made sure that I grounded the ummmm...ground first). I didn't think it would work, but I gave it a shot anyway. The only thing I didn't try is 1). I just found that bit of info 2 minutes ago. Anyone have any ideas? I was surprised at the astounding amount of info out there on the GameGear, but this little shred of info has been impossible for me to find. Hope you guys can help. I'd be most grateful!!

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Posted: Fri May 11, 2001 10:11 pm
	Quote > 4) Years ago in issue #8 of Electronic Gaming Monthly, there was a pic of the GG connected to a TV. They had the (facing the back) right battery compartment filled with a little circuit board. I remember they mentioned that there was a contact they couldn't tell you about that gave video output. I think I lost this issue 9 years ago. This is what the Game Gear looks like: (I bought this Game Gear from someone working at Electronics Arts) The board doesn't look so simple to me :(

Rob Guest	Posted: Fri May 11, 2001 11:26 pm
Rob Guest	Hmmm. I always figured that since the GG was a bit of a suped up Master System, then there should be an output on it somewhere. Also, the LCD runs on typical NTSC standards, unlike a Gameboy, which is probably FAR from simple to connect to a TV. Nice pic though! How much did you snag that system for?

Rob Guest	Posted: Fri May 11, 2001 11:30 pm
Rob Guest	I wonder if that thing is just some kind of RF converter or something. Does it have RCA outputs?

Rob Guest	Posted: Fri May 11, 2001 11:33 pm
Rob Guest	Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-)

Victor Guest	Posted: Sat May 12, 2001 1:50 am
Victor Guest	Quote > This is what the Game Gear looks like: > (I bought this Game Gear from someone working at Electronics Arts) > The board doesn't look so simple to me :( Gee, you've got one of these? That's got to be one of the holiest grails of GG hacking. I'd only heard rumours that this exists before. Have you posted information on it somewhere? Even if the ICs aren't obtainable it'd still be nice to get an idea of how it's done. And hey Bob, what's that you say about the LCD using NTSC signals? Any more info on this?

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Posted: Sat May 12, 2001 9:03 am
	Quote > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-) Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models.

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Posted: Sat May 12, 2001 9:04 am
	Quote > Nice pic though! How much did you snag that system for? Theorically 50$ (quite cheap) but the ok went away with 150$ actually. Oh well.

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Posted: Sat May 12, 2001 9:18 am
	Quote > Gee, you've got one of these? That's got to be one of the holiest grails of GG hacking. See the product number ;-) 105, there wasn't much of them I guess. Quote > I'd only heard rumours that this exists before. I was originally provided to developers. Quote > Have you posted information on it somewhere? Even if the ICs aren't obtainable it'd still be nice to get an idea of how it's done. I'll see what I can get out of it. But the board you see is tighty attached on the behind so it cannot be manipulated easily.

Mike G Joined: 21 Apr 2000 Posts: 598 Location: Newcastle upon Tyne, England	Posted: Sat May 12, 2001 11:36 am
	Quote > Hi Folks, > I'm trying to hook up my GameGear to my TV, and I've heard it is indeed possible. Here's what I know so far: > 1) Pin 36 of the TMS9918A VCD chip is labeled COMVID. Hmmmm. The Game Gear doesn't have a TMS9918A chip. (Nor does the SMS.)The GG's VDP (integrated into one of the large VLSI ICs) is based on the TMS9918A and offers backwards compatibility with the SMS graphics mode, but that's all. There's certainly no composite output available from any pin on the GG's main IC(s). Even the SMS doesn't have this (a Sony CXA1145 encoder is used to generate composite from RGB inside the SMS). There may be RGB outputs and sync signals, but I very much doubt it. Quote > 2) Pin 43 of the Cart slot is labeled TV and I think only refers to the TV tuner cart. Yes (it switches between GG mode and "TV mode", where certain pins of the cart slot function as inputs to the LCD display). Quote > 3) Pins 44 and 45 are labeled respectively TVSNDR and TVSNDL,and they are the TV's right channel and the TV's left channel (left and right channels for video??!!! I thought only audio did that--can anyone clear this up?). Yep, they're audio inputs (left and right channels, for stereo sound) and are used by the TV tuner. I think it's likely to be far from trivial to connect your GG to a TV, unfortunately. Mike

Rob Guest	Posted: Sat May 12, 2001 5:28 pm
Rob Guest	And hey Bob, what's that you say about the LCD using NTSC signals? Any more info on this? Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they converted the SMS architechture to a GG? This would ring especially true since you can use a tv tuner cart with it. I guess the same would go for a turboexpress...

Rob Guest	Posted: Sat May 12, 2001 5:32 pm
Rob Guest	Quote > > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-) > Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models. Hmmmm. Perhaps by using spare SMS parts one could relatively easily implement this then. Perhaps it really is just an (modified?) RF box?!

Victor Guest	Posted: Sun May 13, 2001 1:45 am
Victor Guest	Quote > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I Oh, so there aren't actually NTSC signals running around in there? Quote > believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they converted the SMS architechture to a GG? This would ring Yeah, it would muck up the timing in MS games and cheap GG conversions. I don't want to try and think what happens in 50Hz countries, isn't GG the same anywhere? Meaning that a 50Hz TV tuner would be in a little trouble. Incidently, did anyone figure out how the TV tuner gets its signal in? Surely it's not limited to 16 colors? Even changing the palette every scanline sounds a bit messy.

Rob Guest	Posted: Sun May 13, 2001 7:34 am
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I > Oh, so there aren't actually NTSC signals running around in there? Ummm as far as I know there are. Quote > > believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they converted the SMS architechture to a GG? This would ring > Yeah, it would muck up the timing in MS games and cheap GG conversions. I don't want to try and think what happens in 50Hz countries, isn't GG the same anywhere? Meaning that a 50Hz TV tuner would be in a little trouble. I think the Euro GG are actually PAL, as is the TV tuner (There was a PAL TV tuner, right? Pretty sure there was...think I read about that). Quote > Incidently, did anyone figure out how the TV tuner gets its signal in? Surely it's not limited to 16 colors? Even changing the palette every scanline sounds a bit messy. When the tuner is in, it doesn't use the GG VCD. It just uses the GG's display and the tuner card, along with the GG's power, so color restrictions don't apply....it just uses the screen as a NTSC monitor, afaik.

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	European GG Posted: Sun May 13, 2001 7:57 am
	Quote > I think the Euro GG are actually PAL, European Game Gear runs at 60 hz. I clearly remember that since when I first tried a Master Gear ten years ago (games were running faster) and I can confirm it now. But there's a TV Tuner that works everywhere in Europe EXCEPT FRANCE (damn) because we're using Secam.

Victor Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 10:06 am
Victor Guest	Quote > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The way I see it, why would they change the format when they Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems.

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 10:43 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input?

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 10:49 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input?

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Posted: Thu May 17, 2001 10:52 pm
	Quote > > > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-) > > Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models. > > Hmmmm. Perhaps by using spare SMS parts one could relatively easily implement this then. Perhaps it really is just an (modified?) RF box?! I have no idea what is an RF box, unfortunately: never saw one since we don't use them in France. May I be able to help bringing closer pictures of the board front ?

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 10:54 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 10:57 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 10:59 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 11:09 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

Rob Guest	Re: Gamegear Composite output? Yep! Posted: Thu May 17, 2001 11:30 pm
Rob Guest	Quote > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > way I see it, why would they change the format when they > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this......

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14751 Location: London	Yikes Posted: Thu May 17, 2001 11:33 pm
	... someone's so excited, they hit the Submit button too much :o) Quote > I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. From my experience with flicking between NTSC and PAL standards on my TV card, if it was outputting PAL there'd be no picture. Quote > Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. They're all 60Hz (or 59.94, whatever). There's no need for 50Hz systems when there's no 50Hz output requirement. Not that Sony realised this for the PS2... Sega had more sense with the DC. There are a few games which require PAL display timing, and I think they choke on a Master Gear, the same as when run on an emulator simulating the wrong number of display lines (I don't know the numbers offhand). The vast majority of games never had a proper PAL conversion. Maxim

Rob Guest	AAAHHGG!! Posted: Fri May 18, 2001 12:30 am
Rob Guest	Hey Guys, Really sorry about the repeat...dunno what the hell happenned...the submit button wasn't working...or so I thought. 1000 pardons :-)

Rob Guest	Posted: Fri May 18, 2001 12:37 am
Rob Guest	Quote > > > > Is that strictly video output or is there audio included on there? Looks like a lot of wires on the output connector. :-) > > > Output is an Din connector.. what we call Scart in France. Basically the same kind of output you can find on any Master System, beside the Antenna output on some models. > > > > Hmmmm. Perhaps by using spare SMS parts one could relatively easily implement this then. Perhaps it really is just an (modified?) RF box?! > I have no idea what is an RF box, unfortunately: never saw one since we don't use them in France. > May I be able to help bringing closer pictures of the board front ? That would be great! I bet we's all like to see where those wires lead to! An RF box generally converts the Composite to older tvs that take an RF signal...stands for radio frequency...it's an analog standard of lower picture quality that earlier tvs understand.

Rob Guest	Pinouts Posted: Fri May 18, 2001 4:46 am
Rob Guest	Quote > > > Yeah, it turns out that the scan frequency for the GG LCD is in tune with a NTSC signal. It has the same refresh rate. I believe I found this in one of the tech docs on SMS power. The > > way I see it, why would they change the format when they > > Look what you can get out of one of the upper pins of the four capacitors C22-C25. Just connected straight into the composite input of an NTSC video capture card(bought the GG in a PAL country). I don't know what's wrong with it, maybe someone who knows more about video can tell just from the picture? Some parts of some games have the picture shifted around of sloping or other problems. > You rock, Victor...I will look into this tonight. Thank you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of the probs you mention might be due to the PAL system being used...maybe not...maybe it's the games. Didn't someone mention that all GG's are NTSC? If that is the case, what happens when a Master Gear is used on a PAL game in the GG. Hmmm....wish I was home now instead of at work to test this...... I traced these 4 capacitors to pins 36-39 and 55-58 of the LCD screen. C22 goes to pins 36 and 55. C23 goes to 37 and 56, etc. I haven't traced them backwards yet, but I will. My dad is a TV repairman, and he believes that there is no color sync, judging from the discription of the pic in this thread (he didn't actually see it), hence the garbled screen. I tried tapping these capacitors on my TV and I got some very fuzzy and jittery black and white screens to come up. I had to adjust the vertical to stabilize it as much as I could, but it was still pretty distorted, but I could DEFINITELY make out what I was seeing....sometimes. Sometimes the picture was a bit diagonal, sometimes it would float from the left of the screen to the right and scroll over rapidly, but it was there. This is a great start...I think we might be on a roll!

Victor Guest	Re: Pinouts Posted: Fri May 18, 2001 10:54 am
Victor Guest	Quote > you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of That picture was with it connected to the ground in the GG, but it sort of worked just leaving it hanging. Quote > the probs you mention might be due to the PAL system being I tried it with my TV card set to PAL, NTSC and even SECAM. Only NTSC was reasonable, the others having fields missing, wrong size, etc, but I suppose it depends how strictly your TV adheres to the standards. Actual analog TVs might be more limited, I don't have an NTSC one though. What standard country do you live in? Quote > My dad is a TV repairman, and he believes that there is no color sync, judging from the discription of the pic in this That sounds pretty likely, especially when you notice that what's supposed to be black is black, and what's supposed to be differently colored is different. I can't pretend to know if missing color sync explains why white stays white. It comes out quite cleanly if I turn down the color on my TV. Filtering out the color subcarrier would probably be better though. Quote > seeing....sometimes. Sometimes the picture was a bit diagonal, sometimes it would float from the left of the screen to the right and scroll over rapidly, but it was there. Possibly there's no vert/horiz sync pulses either, I suspect my TV card is cleverly guessing where it thinks they should be, the way some other images come out suggests this quite strongly. Do you have a scope? If not, when I find the time I'll try and see what's actually going on, and check other pins too, parts of the video signal might be seperate and in that case probably out of spec too. By the way, in MS mode, you get a bigger picture, same pixel size. But that can be changed to what the LCD shows depending on how you use the MS/GG input. It's really odd.

Victor Guest	Re: AAAHHGG!! Posted: Fri May 18, 2001 10:59 am
Victor Guest	Quote > Really sorry about the repeat...dunno what the hell happenned...the submit button wasn't working...or so I thought. I've noticed that too.

Rob Guest	Re: Pinouts Posted: Fri May 18, 2001 5:11 pm
Rob Guest	Quote > > you! Did you ground anything? OR did you just use one connector straight to the center of the input? I think some of > That picture was with it connected to the ground in the GG, but it sort of worked just leaving it hanging. I tried it on my TV with an RF box and it came in like crap. I tried it on a good TV with composite, and I actually got some clean pictures sometimes (still black and white). Even onthis TV though, they were still jittery. I let the game run through the demo and the title screen (Sonic Chaos), and it usually was stable at the title screen, sometimes stable at the demo, and usually screwed up where Sonic and Tails run after Eggman/Robotnik. Other times, it did whatever the hell it wanted. It may be just coincidence, but I seemed to get a better pic out of C23... By the way, the bottom pins of these 4 Capacitors are ground, but they also lead to many other places (which all seem to be common to the four of them....). I couldn't get a signal at all unless I had a the ground grounded. Quote > > the probs you mention might be due to the PAL system being > I tried it with my TV card set to PAL, NTSC and even SECAM. Only NTSC was reasonable, the others having fields missing, wrong size, etc, but I suppose it depends how strictly your TV adheres to the standards. Actual analog TVs might be more limited, I don't have an NTSC one though. What standard country do you live in? I live in USA...NTSC. Quote > > My dad is a TV repairman, and he believes that there is no color sync, judging from the discription of the pic in this > That sounds pretty likely, especially when you notice that what's supposed to be black is black, and what's supposed to be differently colored is different. I can't pretend to know if missing color sync explains why white stays white. It comes out quite cleanly if I turn down the color on my TV. Filtering out the color subcarrier would probably be better though. It seems there is another problem other than the color sync though. Even if the colors were correct, the signal is still wacked-out. Sometimes it just doesn't display what it's supposed to, but other scenes are correct. It's usually the same screens that screw up and the same scenes that display relativley stabily. Quote > > seeing....sometimes. Sometimes the picture was a bit diagonal, sometimes it would float from the left of the screen to the right and scroll over rapidly, but it was there. > Possibly there's no vert/horiz sync pulses either, I suspect my TV card is cleverly guessing where it thinks they should be, the way some other images come out suggests this quite strongly. Maybe, but like I said, some scenes were correct (but black and white). Quote > Do you have a scope? If not, when I find the time I'll try and see what's actually going on, and check other pins too, parts of the video signal might be seperate and in that case probably out of spec too. I do have a scope somewhere, but I wouldn't recognize the signals I see :-) I wish I could hookit to my computer, because at least the I could offer screen grabs of the signals. Quote > By the way, in MS mode, you get a bigger picture, same pixel size. But that can be changed to what the LCD shows depending on how you use the MS/GG input. It's really odd. Hmm.. not sure If I understand what you mean here. Strange stuff indeed!

Victor Guest	Re: Pinouts Posted: Sat May 19, 2001 2:58 am
Victor Guest	Quote > clean pictures sometimes (still black and white). Even onthis This could fit in with the no color sync theory as the TV might not find it and assume it's a black and white signal which isn't meant to have color sync anyway. Quote > stable at the title screen, sometimes stable at the demo, and usually screwed up where Sonic and Tails run after Eggman/Robotnik. Other times, it did whatever the hell it Sounds much like Sonic 2 did for me. This picture is supposed to be round, but it always comes out like that. My guess is that the TV may be mistaking the right hand edge of the circle with an h-sync pulse and starting the next line there. signals I see :-) I wish I could hookit to my computer, because at least the I could offer screen grabs of the signals. No video capture card? No digital camera? And you say you live in America? Something doesn't quite add up :)

Victor Guest	Re: Pinouts Posted: Sat May 19, 2001 3:03 am
Victor Guest	Quote > > By the way, in MS mode, you get a bigger picture, same pixel size. But that can be changed to what the LCD shows depending on how you use the MS/GG input. It's really odd. > Hmm.. not sure If I understand what you mean here. Strange stuff indeed! This is the MS game Hang-On running in MS mode. That's the full TV screen. And yep, the track is supposed to be curved like that.

Rob Guest	Re: Pinouts Posted: Sat May 19, 2001 6:10 pm
Rob Guest	Quote > > clean pictures sometimes (still black and white). Even onthis > This could fit in with the no color sync theory as the TV might not find it and assume it's a black and white signal which isn't meant to have color sync anyway. > > stable at the title screen, sometimes stable at the demo, and usually screwed up where Sonic and Tails run after Eggman/Robotnik. Other times, it did whatever the hell it > Sounds much like Sonic 2 did for me. This picture is supposed to be round, but it always comes out like that. My guess is that the TV may be mistaking the right hand edge of the circle with an h-sync pulse and starting the next line there. > signals I see :-) I wish I could hookit to my computer, because at least the I could offer screen grabs of the signals. > No video capture card? No digital camera? And you say you live in America? Something doesn't quite add up :) Heh heh. That's because I spent all my money on video games! Actually, I DO have a digital camera attachment for my Palm IIIc. I will try to get some screen pics (glad you reminded me of that!). Don't worry, I generally only use my Palm for videogames, heh heh (plus I won it at work, so no money spenton things other than videogames:-). If you want a real laugh, would you believe my home system is a P166 w/40mb ram!? I think your theory on the H-sync pulse is probably right. I hadn't thought of that. Still, I'm not sure that it explains why some scenes are displayed differently each time, but some are always the same. If we do find a C-sync output, how do we tie it in with the composite? I'm pretty sure rgb and SCart tvs do this (only on seperate pins), but I've never used an scart or rgb tv...so I'm not sure how the pinswould tie together to make one composite output. Do we just tie them together in a composite signal, or must they be somehow seperated like scart/rgb?

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	RF box Posted: Sun May 20, 2001 8:32 am
	Quote >>> I have no idea what is an RF box, unfortunately: never saw one since we don't use them in France. >> May I be able to help bringing closer pictures of the board front ? > That would be great! I bet we's all like to see where those wires lead to! An RF box generally converts the Composite to older tvs that take an RF signal...stands for radio frequency...it's an analog standard of lower picture quality that earlier tvs understand. Then RF is the antenna plug, right ? It doesn't output RF signal, for sure. I'll give a look to the system later today.

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14751 Location: London	Re: RF box Posted: Sun May 20, 2001 7:20 pm
	Quote > Then RF is the antenna plug, right ? RF = Radio Frequency, ie. same as antenna signals. Maxim

unfnknblvbl Joined: 12 Jul 1999 Posts: 891	Re: RF box Posted: Tue May 22, 2001 4:23 am
unfnknblvbl Joined: 12 Jul 1999 Posts: 891	Quote > > Then RF is the antenna plug, right ? > RF = Radio Frequency, ie. same as antenna signals. > Maxim All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D ~unfnknbvbl

Rob Guest	Re: RF box Posted: Tue May 22, 2001 4:50 am
Rob Guest	Quote > > > Then RF is the antenna plug, right ? > > RF = Radio Frequency, ie. same as antenna signals. > > Maxim > All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D > ~unfnknbvbl Some tv's don't allow that. Your's is probably newer, so it new what you were doing and translated the signal. SOme tv's only will accept the antenna signal.

Rob Guest	Re: Pinouts Posted: Tue May 22, 2001 8:22 am
Rob Guest	Quote > If we do find a C-sync output, how do we tie it in with the composite? I'm pretty sure rgb and SCart tvs do this (only on seperate pins), but I've never used an scart or rgb tv...so I'm not sure how the pinswould tie together to make one composite output. Do we just tie them together in a composite signal, or must they be somehow seperated like scart/rgb? Well, I couldn't get my Palm digital camera attachment to take any good pictures because the room my tv is in has awful lighting. However, I do have some news to report. I'm pretty sure that 3 out of the 4 capacitors is R, G, and B. The reason is that I would tap all four of them at once and certain "color" shades went away (remember, they are all black and white) as I took each contact away. I'm not exactly sure what the fourth is, as it gives a video signal too, I just don't know exactly what it's doing that' different than the others. I tapped every pin on the LCD and nothing seemingly significant happenned except for the LCD pins tied directly to the 4 capacitors. Also, I have more evidence to reinforce the theory that it is truly the color sync we are missing. Whenever the background is black, or if there is a great majority of black on the screen, the picture starts to roll rapidly like in the Sonic 2 pic in this thread. If the screen is very bright, or white, the picture is nearly perfect exept there's no color, of course. This type of occurence was apparent in Sonic 2, Sonic Chaos, Devilish, and in Cosmic Spacehead. So, like I said earlier, I wouldn't know a color sync signal if it bit me in the behind, so if we find the pin that gives csync, what do we do with it to make it work in a composite signal?

unfnknblvbl Joined: 12 Jul 1999 Posts: 891	Re: RF box Posted: Tue May 22, 2001 1:42 pm
unfnknblvbl Joined: 12 Jul 1999 Posts: 891	Quote > > > > Then RF is the antenna plug, right ? > > > RF = Radio Frequency, ie. same as antenna signals. > > > Maxim > > All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D > > ~unfnknbvbl > Some tv's don't allow that. Your's is probably newer, so it new what you were doing and translated the signal. SOme tv's only will accept the antenna signal. Hmm... well, it's worked on all the TVs I've tried it on.. even a crappy old TV that had a rooted picture tube that you could barely see anything on, which was so old that it had wood panelling on the sides... can't get much older than that.. But then, it may because of the PAL signal... ~unfnknblvbl

Rob Guest	Re: RF box Posted: Tue May 22, 2001 7:38 pm
Rob Guest	Quote > > > > > Then RF is the antenna plug, right ? > > > > RF = Radio Frequency, ie. same as antenna signals. > > > > Maxim > > > All the RF unit does is let you have two inputs into one 'Antenna in' port in the back of your TV.. you can just take a cable and plug it straight into your TV from your SMS and it will work fine.. I do it all the time 'coz my original RF unit was rooted, so I hacked up a cable of my own :D > > > ~unfnknbvbl Hmmm. Strange. Can't hook my systems up to any of my old tv's w/o the Rf modulator box Quote > > Some tv's don't allow that. Your's is probably newer, so it new what you were doing and translated the signal. SOme tv's only will accept the antenna signal. > > Hmm... well, it's worked on all the TVs I've tried it on.. even a crappy old TV that had a rooted picture tube that you could barely see anything on, which was so old that it had wood panelling on the sides... can't get much older than that.. > But then, it may because of the PAL signal... > ~unfnknblvbl

Victor Guest	Some results. Posted: Wed May 23, 2001 9:59 am
Victor Guest	I had a brief look on a scope today but I was a bit pressed for time so didn't get a lot done. I only paid attention to C25, the other three seem similar. It's 4.8V peak-peak compared to 1V for NTSC or PAL, but the 75ohm input on a TV would no doubt reduce that significantly, didn't check how much though. It doesn't sync pulses, at least not standard ones, apparently no color burst(sync) either. Where there's picture data it goes all the way between 0 and 4.8V. Between lines and I think also black regions are 0V. A real signal should only go to 0 during sync pulses with black being about 1/4 of the maximum voltage. The line frequency is 15.71kHz +/- 0.2kHz, which more or less matches NTSC's 15.734264 kHz, and is way off PAL's 15.625kHz. The picture in this message shows what looks like two fields (a field being one half of the interlaced frame - every second line), grey parts are where it's shooting up and down too fast to see. But the width implies a refresh rate of about 125Hz compared to 60Hz for NTSC. It could be 2*60Hz, but I don't know what that would mean. Either way I'm suprised our TVs handle it as well as they do. I'll try to have another go in a few days and hopefully get some better data and check other parts of the circuit for possible sync pulses. Quote > If we do find a C-sync output, how do we tie it in with the composite? I'm pretty sure rgb and SCart tvs do this (only on seperate pins), but I've never used an scart or rgb tv...so I'm not sure how the pinswould tie together to make one composite output. Do we just tie them together in a composite signal, or I don't know how it's supposed to be done, but for a cheap answer you can probably just do that if you're generating one of the signals, maybe with some series resistors too. Shouldn't be a major problem.

Victor Guest	Better measurements this time. Posted: Thu May 24, 2001 2:27 pm
Victor Guest	Aar yaah, here we go again. I made a mistake with the 125Hz scan rate in my last post, it turns out it really is NTSC's ~60Hz after all, which is most excellent. To convert the C25 signal into NTSC it would need horozontal sync, vertical sync and color burst added, and possibly be reduced in amplitude slightly, but that's trivial. Horozontal sync pulses could easily be generated from point E (see below) to keep every line in the correct horozontal position on the screen. With just this it would probably be fairly usable. I'll try to work on a circuit for it. I don't know about vertical sync, but that's not so important, could be obtained from C25 with a bit of cleverness. Don't know about color burst either, that is assuming it even has the correct frequency and format of the color subcarrier. It's possible that it already has this, but I just didn't find it, and a TV wouldn't find it with no h-sync, it's only a couple of us wide, just before the image data on each line. Line frequency fH = 15.700kHz +/- 0.002kHz. NTSC is 15.734kHz. Not sure how I got the dubious value in my previous post, but it was using a different frequency counter. Don't trust the uncertainty, but even if it is correct I doubt any TVs will have a problem with the slightly different frequency. In case you don't know what I'm on about, the line frequency is the number of horozontal lines per second, or to put it another way, the inverse of the time taken to scan one line across the screen. Here are the signals I've measured(all relative to ground) in case they're any use, beware of the ASCII art: Non grounded pin of C25 where the actual video data is: Lines __4.8V open cct, 1V with 75ohm load. \| \|\|\| \|\| \| \|\| \|\|\|\|\|\|\|\|\| \|\|\|\|\| \|\|\|\|\|\|\|\|\|\| \|\|\|\|\| ___\|\|\|\|\|\|\|\|\|\|___\|\|\|\|\| __0V \|<--- fH --->\| \|<------>\| Image data, width varies. Fields __4.8V open cct, 1V with 75ohm load. \|\|\|\|\|\| \|\|\| \|\|\|\|\|\|\|\|\|\| \|\|\|\|\| \|\|\|\|\|\|\|\|\|\| \|\|\|\|\| ___\|\|\|\|\|\|\|\|\|\|___\|\|\|\|\| __0V \|<---------->\| 61Hz +/- 2Hz. \|<------>\| Image data, width varies. Point E: ___ ___ __4.8V +/- 0.4V \| \| \| \| \| \| \|___\| \|___ __0V \|<-fH ->\| Rising edges are synchronized with the center of the space between lines. This is another signal that pops up in many different places and may possibly be relevent, but I don't have any idea how: Point B: ___ ______________ ___ __5.2V +/- 0.4V \| \| \| \| __3.6V +/- 0.4V \|\|\|\| \|\|\|\| \|\|\|\| \|\|\|\| \|\|\|\| \|\|\|\| __1.0V +/- 0.4V __0V \|<----- fH ------>\| -->\| \|<-- 10us +/- 2us -->\|\|<---- 7.7MHz +/- 0.6MHz The center of each 7.7MHz burst is synchronized with the center of the image data in a line. Where are points B and E? Looking from the back of the unit, immediatly below R22 are three holes in a diagonal straight line, I call the left most one point E. Below and to the left of these is a diagonal row of four holes, point B is the second one from the left. Brief description of what a video signal looks like.

Victor Guest	Re: Pinouts Posted: Thu May 24, 2001 2:51 pm
Victor Guest	Quote > sure that 3 out of the 4 capacitors is R, G, and B. The reason is that I would tap all four of them at once and certain "color" shades went away (remember, they are all black and white) as I took each contact away. I'm not exactly sure what the fourth is, as it gives a video signal too, I just don't know exactly what it's doing that' different than the others. Ah, that'd be nice, is the fourth C25? That's the one that looks different to me. I'm not too sure how you're saying you set it up, but I suppose you'd need a TV with RGB inputs to check it properly, maybe a VGA monitor would work, but that sounds pretty iffy. Quote > So, like I said earlier, I wouldn't know a color sync signal if it bit me in the behind, so if we find the pin that gives csync, what do we do with it to make it work in a composite signal? From what I've read it's about 10 cycles of 3.58Mhz at the beginning of each scanline. How to connect it would depend. One way might be to pass it through an amplifier to reduce the output impedance, then connect that straight into the main video line so it can just force whatever else is there into submission. Or maybe do without the amp - knowing how tolerant TVs are of out-of-spec signals pretty much anything could work. Though it might also need phase shifting, since the phase of the color sync is quite critical. I believe the GG's (and SMS's) CPU clock frequency is exactly the same as the NTSC color subcarrier's which means if we can just find a clock line, that may do as the beginning of a color sync.

Rob Guest	Re: Pinouts Posted: Fri May 25, 2001 4:50 am
Rob Guest	Quote > > sure that 3 out of the 4 capacitors is R, G, and B. The reason is that I would tap all four of them at once and certain "color" shades went away (remember, they are all black and white) as I took each contact away. I'm not exactly sure what the fourth is, as it gives a video signal too, I just don't know exactly what it's doing that' different than the others. > Ah, that'd be nice, is the fourth C25? That's the one that looks different to me. I'm not too sure how you're saying you set it up, but I suppose you'd need a TV with RGB inputs to check it properly, maybe a VGA monitor would work, but that sounds pretty iffy. > > So, like I said earlier, I wouldn't know a color sync signal if it bit me in the behind, so if we find the pin that gives csync, what do we do with it to make it work in a composite signal? > From what I've read it's about 10 cycles of 3.58Mhz at the beginning of each scanline. > How to connect it would depend. One way might be to pass it through an amplifier to reduce the output impedance, then connect that straight into the main video line so it can just force whatever else is there into submission. Or maybe do without the amp - knowing how tolerant TVs are of out-of-spec signals pretty much anything could work. Though it might also need phase shifting, since the phase of the color sync is quite critical. > I believe the GG's (and SMS's) CPU clock frequency is exactly the same as the NTSC color subcarrier's which means if we can just find a clock line, that may do as the beginning of a color sync. If that is the case (which I would have never thought of), what about the pins of the clock case itself? The little metal-coated can thing next to the lcd would be a direct clock line, I think. Aren't those things made of a quartz crystal or something? I think I tried connecting this with one of the output capacitors and it didn't give any csync...maybe you guys might find otherwise.

Victor Guest	Re: Pinouts Posted: Fri May 25, 2001 5:11 am
Victor Guest	Quote > If that is the case (which I would have never thought of), what about the pins of the clock case itself? The little metal-coated can thing next to the lcd would be a direct clock line, I I suppose so, don't know much about crystals. But that'll be a continuous oscilation, it'd have to be switched on briefly just when it's needed, might need the waveform modified too, who knows. Though that all sounds doable. What I'm worried about is that it might end up very complicated (ie expensive) while there may be a much easier way which Sega's one uses. I wish we knew where that PCB of Zoop's is connected to, or anything else about it, that'd be a huge plus.

Rob Guest	Re: Pinouts Posted: Fri May 25, 2001 7:41 am
Rob Guest	Quote > > If that is the case (which I would have never thought of), what about the pins of the clock case itself? The little metal-coated can thing next to the lcd would be a direct clock line, I > I suppose so, don't know much about crystals. But that'll be a continuous oscilation, it'd have to be switched on briefly just when it's needed, might need the waveform modified too, who knows. Though that all sounds doable. What I'm worried about is that it might end up very complicated (ie expensive) while there may be a much easier way which Sega's one uses. I wish we knew where that PCB of Zoop's is connected to, or anything else about it, that'd be a huge plus. Yeah, he mentioned he'd try to get some scans of it soon. That would be really good. I did check out that clock chip (that little metal box is the clock, as it turns out). There is a row of 1 capacitor then two Resistors, and below it is one more capacitor to the right of the clock. See the wonderful ASCII art below: ______ \| C \| C? R? R24 \| L \| \| O \| \| C \| C?? \| K \| \|_____\| These ?s are because the number of these are obscured by the LCD backlight leads. Anyway, the clock has two pins on the underside of the board. The one that is closest to the bottom of the board leads to the top and bottom of R? and the top of R24. The top lead of the clock leads to the top of C? and the bottom of R24. Tying either of these to any of C 22-25 did nothing but short out the GG.

Rob Guest	Re: Pinouts Posted: Fri May 25, 2001 7:43 am
Rob Guest	That would be really good. I did check out that clock chip (that little metal box is the clock, as it turns out). There is a row of 1 capacitor then two Resistors, and below it is one more capacitor to the right of the clock. See the wonderful ASCII art below: Quote > ______ > \| C \| C? R? R24 > \| L \| > \| O \| > \| C \| C?? > \| K \| > \|_____\| OK, so the ascii art didn't turn out as planned. Just move the \|s over to line up with the right edge of the _s and it should be clearer. Quote > These ?s are because the number of these are obscured by the LCD backlight leads. Anyway, the clock has two pins on the underside of the board. The one that is closest to the bottom of the board leads to the top and bottom of R? and the top of R24. The top lead of the clock leads to the top of C? and the bottom of R24. Tying either of these to any of C 22-25 did nothing but short out the GG.

Rob Guest	Re: Better measurements this time. Posted: Fri May 25, 2001 7:48 am
Rob Guest	Quote > Aar yaah, here we go again. > Horozontal sync pulses could easily be generated from point E (see below) to keep every line in the correct horozontal position on the screen. With just this it would probably be fairly usable. I'll try to work on a circuit for it. Point E turns out to be a lead off of C20. Why woud this make a hsync? It didn't do anything when I tied it C22-25, btw. Quote > I don't know about vertical sync, but that's not so important, could be obtained from C25 with a bit of cleverness. I think if we can get the v or h sync, maybe the other would follow (at least on smarter tv's...who knows). Maybe not. Quote > Below and to the left of these is a diagonal row of four holes, point B is the second one from the left. This leads to the bottom of R19.

Rob Guest	Re: Better measurements this time. Posted: Fri May 25, 2001 7:57 am
Rob Guest	Time to add some real confusion to the mix. I got my Master Gear converter today (I won it in an ebay auction that also included a Master Link cable to use a Second player in MS games!). I tried connecting Leads c22-25 to my tv and got some very strange results. It did fill the screen as it's supposed to, but I actually had it in color! The wrong colors, though. I got the best signal of C25. C23 was good too, but the best signal was with C23 and C25 together. C22 and 24 did nothing much. I think 22 made the screen roll vertically and made it very dark at that. Anyway, I was playing Alex Kidd IMW and the sky was green, and alex had black hair. When I added C23 to this, alex's hair seemed to be the right color and the sky was still green, only a little more yellow. The weird thing is, Red, Green, and Blue did appear on onscreen objects, but it seemed they weren't in the right places. Even though it had some items right (alex's colors). I Don't know what to make of this. I really didn't expect any color out of this. I hope this doesn't set us back....

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