I need RGB help!

[Blades]

I'm not sure if this is the correct place to post this, so I apologize if this is the incorrect subforum..

I hate to start off my forum activity by asking a "help me" question but it seems you people are complete experts at this, so I hope it's not too much trouble.

My mission is this: I want to play my Sega Genesis (model 1) in RGB quality on an authentic RGB CRT monitor.

I have created this list of required items:
-Sega Genesis 1
-Commodore 1084s RGB monitor (reasonable size + acceptable price, but if anyone has better suggestions please suggest)
-The cable to connect these two pieces of hardware

The cable is where I run afoul. How exactly do you connect the Genesis to the monitor?

I have not found any cables for sale that connect directly to the Commodore so I assume I need to *build* a specialized cable? I have read the RGB primer on this website (fantastic site by the way) and it mentions purchasing the SCART cable for your system of choice.

Assuming I have said cable, and chop off the SCART end to connect the Commodore end; how do I know which wires are which in the cable, are they color-coded or something? Are there any tutorials on the web for a complete beginner like me?

As for the Commodore end, I assume I have to buy the end from someplace like Radioshack. If that is the case, does the Commodore input have a name? Or do I just try to visually match it. I've also read conflicting reports on the internet of it being "easy" to connect a Genesis 1 to a Commodore because they have the same connector?

In any case, I'm usually pretty careful and successful if I attempt something, but in this case I have simply no idea what to do.

Thanks to you all.

[albino_vulpix]

I'm not sure if this is the correct place to post this, so I apologize if this is the incorrect subforum..

I hate to start off my forum activity by asking a "help me" question but it seems you people are complete experts at this, so I hope it's not too much trouble.

My mission is this: I want to play my Sega Genesis (model 1) in RGB quality on an authentic RGB CRT monitor.

I have created this list of required items:
-Sega Genesis 1
-Commodore 1084s RGB monitor (reasonable size + acceptable price, but if anyone has better suggestions please suggest)
-The cable to connect these two pieces of hardware

The cable is where I run afoul. How exactly do you connect the Genesis to the monitor?

I have not found any cables for sale that connect directly to the Commodore so I assume I need to *build* a specialized cable? I have read the RGB primer on this website (fantastic site by the way) and it mentions purchasing the SCART cable for your system of choice.

Assuming I have said cable, and chop off the SCART end to connect the Commodore end; how do I know which wires are which in the cable, are they color-coded or something? Are there any tutorials on the web for a complete beginner like me?

As for the Commodore end, I assume I have to buy the end from someplace like Radioshack. If that is the case, does the Commodore input have a name? Or do I just try to visually match it. I've also read conflicting reports on the internet of it being "easy" to connect a Genesis 1 to a Commodore because they have the same connector?

In any case, I'm usually pretty careful and successful if I attempt something, but in this case I have simply no idea what to do.

Thanks to you all.

It appears to me that the Commodore 1084 had several RGB monitors with different connectors. Which does your monitor have?

Once you have that sussed out, you need to then look at the Genesis end. Buying a ready-made SCART cable is a good idea, since the Genesis connector is slightly incompatible with the ones you'll find in stores.

Once you have the connectors, there's the added issue of the sync signal. Some Commodore 1084 monitors need seperate horizontal/vertical sync, but the Genesis doesn't output these signals. the LM1881 is your firend here. Run the Genesis' composite video (not composite sync, it's screwed up in the Genesis) into the chip with the components shown on that page, and you'll have your h and vsync signals.

At this point, it's just a matter of connecting the dots. You can't rely on the colours of the wires inside your Genesis cable matching convention (don't assume the green wire has green video in it), so you'll need to work that out with a multimeter, or a light connected to a battery, or whatever. Connect the necessary resistors and capacitors as shown here.

Sounds like a fair mountain to climb, but it's worth it

[Blades]

Thanks for the reply!

I have the 1084S-P which has a 6-pin DIN analog RGB input. I believe I've figured out the majority of the problems, but I do not understand a few things with the LM1881. Firstly, where do I find it? Is there a US based distributor of these chips.

Also, how does such a cable look after it's done? Is it a connector > cable > box with LM1881? > cable > connector setup?

As for the diagram I understand the composite video in, +5v in, and the H and V sync out; but what are those other outputs or inputs like Odd/even output, Rset, and Burst/Back Porch output?

I also know next to nothing about electronics so I'm making mostly assumptions here. Is the bottom left wire to ground in the picture? and what are those parallel lines and squiggly lines?

I should really take a basic electronics course.

As for the Gen. cable, that's a shame. Can I buy *any* Gen. 1 cable and use it, or must it be SCART (the reason I'm asking is because shipping to US from UK is quite a lot for something I'll chop up!)?

EDIT: ! What are those things between the cables on the Red, Green, and Blue lines on that SCART picture? There have to be things *between* the Genesis and the monitor?

[albino_vulpix]

Thanks for the reply!

I have the 1084S-P which has a 6-pin DIN analog RGB input. I believe I've figured out the majority of the problems, but I do not understand a few things with the LM1881. Firstly, where do I find it? Is there a US based distributor of these chips.

There's plenty of these on eBay.

Also, how does such a cable look after it's done? Is it a connector > cable > box with LM1881? > cable > connector setup?

That's how I would do it.

As for the diagram I understand the composite video in, +5v in, and the H and V sync out; but what are those other outputs or inputs like Odd/even output, Rset, and Burst/Back Porch output?

Odd/even and burst/back porch you can ignore. You do need the resistor and capacitor on the reset pin. As for what they do exactly, I don't know.

I also know next to nothing about electronics so I'm making mostly assumptions here. Is the bottom left wire to ground in the picture? and what are those parallel lines and squiggly lines?

The downward arrow is ground, the squiggle lines resistors, and the parallel lines capacitors.

I should really take a basic electronics course.

As for the Gen. cable, that's a shame. Can I buy *any* Gen. 1 cable and use it, or must it be SCART (the reason I'm asking is because shipping to US from UK is quite a lot for something I'll chop up!)?

Any Genesis cable with the RGB wires in it. An AV cable won't have these wires, so SCART is the best you're likely to find.

EDIT: ! What are those things between the cables on the Red, Green, and Blue lines on that SCART picture? There have to be things *between* the Genesis and the monitor?

Resistors and capacitors, and yes they are needed.

[Blades]

Ok, I will try my best to build the cable successfully. If I have any problems, I will post here. Thank you very much for your help  .

EDIT: Looking at that SCART - Genesis diagram, I don't understand how SCART factors in? Is the SCART end supposed to be the monitor in my scenario? In that case I am probably excluding audio, +5 (That goes to the LM1881 correct?), and composite video (also to LM1881).

[Endymion]

If you go to National Semiconductor's site you can request "samples" of the LM1881. They will gladly send you up to five in the mail free of charge.