RGB cable help for Sega Genesis Model1

[davidmt]

I am a total noob when it comes to RGB, so I am humbly asking for some help or at least a push in the right direction with finding the right cables.

I have a Sony GVM-2020 monitor and am very interested in connecting my Model1 Genesis (and also SNES) to it. I don't think I have the skills to build my own cables so I'm looking for other ideas.

I attached a picture of the back of the monitor. As you can see there are a lot of options here. I'm thinking the best picture would be through the 4 BNC cables, but again, I really don't know. Also, I am from the USA. I have seen a lot of discussions regarding SCART but unless I am mistaken, I don't think that would work for me.

I have been searching all over looking for ideas, the only thing I came up with was a link from the Neo Geo forums showing a monitor with cables for sale from 2008.
http://www.neo-geo.com/forums/showthread.php?t=183215. It at least showed me what I want to do is possible, but I don't know where I can find cables like these.

If anyone could enlighten me on what the best approach would be, I would REALLY appreciate it.

[tomwaits]

If you're planning to connect multiple consoles via RGB then using standard SCART cables, a standard SCART switchbox, and a single custom SCART->GVM RGB cable is probably the best approach. Saves wiring up a bunch of individual cables and cable swapping.

You'd need to build/buy either a SCART-> 9-pin GVM RGB or SCART-> BNC cable. BNC might be slightly better signal quality, but at the low resolution of old consoles I don't think there would be much difference. If you've got basic soldering tools, I could give you a quick walkthrough. It's pretty simple to build a cable.

One thing to be aware of with the wiring... there are two different ways to get sync timing for RGB displays: composite video and composite sync. They're different signal formats. I think the GVM can handle either, but don't know if the BNC input requires bare csync? Some RGB monitors are very finicky about the type and strength of the sync input. There's lots of great info at gamesx.com.

Also, there are a few caveats with a Genesis model 1. The model 1 doesn't output stereo sound from the A/V connector. You probably want to pull stereo from the headphone jack into the SCART cable. Also, if you ever plan to use RGB with a Sega CD or 32X you'll need a model 2/3 Genesis A/V->SCART cable. I usually play on my model 1 Genesis, but my SCART cable has a model 2/3 A/V plug. When I use only the model 1 Genesis I use a standard 32X model 1 adapter stub to feed the model 2/3 SCART cable input. If I use my CDX or 32X, just remove the adapter stub and connect the same cable directly to either of those Genesis variations. More flexible solution if you're building or buying a SCART cable and have an interest in the Genesis add-ons...

RGB switchboxes also have some potential issues. If you get one make sure it has full RGB on all inputs. Breakout RCA stereo jacks on the switchbox are a nice feature too. Also make sure the switchbox isn't powered since you'd probably need a power converter. There are some decent 3 or 5 input SCART switchboxes, but you need to make sure they'll fit your setup.

It takes some effort to get started, but upgrading old consoles to RGB output is worth it.

[Icarus Moonsight]

You are more than likely going to have to build an adapter or do some sort of wiring work, or have someone else do it for you.

An option that I considered was taping the RGB and Composite lines from each console and wiring them to 4 RCA jacks on the consoles exterior. Then, get RCA to BNC adapter dongles and just use a standard composite and component RCA cable for hooking it all up.

It's a lot of work on the front end (which I had a reason to do), but I just decided to go with the less redundant route of SCART cables and a SCART to BNC homemade cable to start.

The initial long term plan was to use the console RGB signal output to run through a DIY converter box to output component, s-vid, composite and a VGA plug straight RGBhv signal output eventually (w/ composite sync, split and cleaned). I didn't abandon the plan (I did abandon the RCA part), I just wanted to play the games sooner than the long term plan allowed for. So, building the converter box, it's coming later. SCART is not nearly as daunting as it seems at first.

This might help you: http://www.epanorama.net/faq/vga2rgb/scart.html

[davidmt]

Thanks guys for the help. I will definitely look into these suggestions.

Someone also recommended that I do the following:
- Buy a BNC to VGA cable
- Buy a Genesis Model 1 to SCART, cut off the SCART and wire to VGA. This would give me flexibility for multiple consoles (I could also buy a SNES to SCART and wire to VGA).
Do you think this is a worth-while option?

I think I also read that the SCART switch box don't do a very good job and lose visual quality. Any truth to that? I suppose it would have a lot to do with how good the box is.

Tom, the GVM-2020 only does mono so I'm not too concerned about stereo right now. I do have a Sega-CD and would like to use it also but for now I was concentrating just on the base Genesis (I also have a Model 3). I figure I would start off slow as this RGB stuff is so new to me. Wow, I thought I knew cabling and what-not but this RGB stuff is like a whole different world.

[tomwaits]

Whether you transition to SCART or VGA between the device output and the monitor input doesn't really matter... it's just wires/connectors. But, you'd need to replace the SCART connector with a 15-pin VGA connector for each console. If it's just two consoles that's not too bad, but once you get one console running RGB you'll want them all running RGB. Might be better to plan ahead. 3rd party SCART cables are cheap and once you've got SCART->GVM working additional consoles are easy to add.

Signal loss would depend on the switchbox model and cable lengths. I'm using a pair of Hama 3 input SCART RGB switchers and everything looks great.

Most monitors don't have audio on the RGB input, so it has to be handled separately from the RGB cable. That's why I mentioned the convenience of having RCA audio breakouts on the switchbox. Audio can be routed to the monitor, external speakers, or hifi directly at the SCART switchbox and it's a common connection for any connected consoles.

[davidmt]

Tom, I can't thank you enough for your guidance. As I mentioned, this stuff is totally foreign to me.

You are right, its better to do the wiring once, then I can just buy standard SCART cables for my various consoles. The hard part will be putting together the BCM to SCART cable.

Does this look like a decent switchbox?
http://cgi.ebay.com/Hama-42945-SCART...ht_2111wt_1160

[tomwaits]

That Hama switchbox is the same model that I'm using. Works great. I have two of them, one connected to each of my monitor's RGB inputs. I got mine from ebay Germany almost 2 years ago and I paid less than that ebay UK listing you linked. I think the same or similar switchbox was distributed by Philips in the UK so you might find the Philips model for less on ebay.uk?

EDIT: Also, if you're going to order a SCART cable for a US SNES, make sure to order a Euro Gamecube SCART cable. The Euro SNES uses resistors on the output lines, the US SNES needs the same capacitors used by the Euro Gamecube. Check out the last chart on this page:
http://gamesx.com/wiki/doku.php?id=av:nintendomultiav

(US N64s and Gamecubes won't output RGB at all without console mods)

[davidmt]

Thanks. I have one more question ...
I found this cable on ebay that would connect to the DB9 input rather than BNC, could this also be an option for my monitor?
http://cgi.ebay.com/ws/eBayISAPI.dll...ht_2900wt_1141

[tomwaits]

You'd have to find/compare pinouts for each monitor's DB9. I don't know if there was any standard for DB9 RGB back then, or which monitors shared common pinouts. That's the right idea though... and having the RCA stereo breakouts on the cable would remove the need for having them on the switchbox, or vice versa.

If you end up building your own cable to the GVM's DB9, SCART connectors are VERY easy to solder. The pins are far apart and usually have V shaped grooves inside the shell that make soldering simple. If you decide to build your own, I'd find a short, fully wired DB9 to DB9 cable... chop off and strip one end, then get a male SCART connector and match up connections.

[davidmt]

I found the pinouts for both the Sony and Philips 8833. Most line up but there are some differences for some - do I care about all pin definitions?

---GVM----8833

1--GND----GND
2--NC------GND
3--R--------R
4--G--------G
5--B--------B
6--NC------FB
7--NC------HV
8--H/HV---H
9--V--------V

NC = no connection
H = Horizontal Sync
HV = Composite Sync
V = Vertical sync

FB = Fast Blanking

[tomwaits]

The only pins you'd need to worry about are GND, R, G, B, and HV (csync). Looks like you'd need to move the csync wire from pin 7 to pin 8 inside the DB9 hood. From looking at the pic in the ebay listing it doesn't look like the hood opens, you may want to ask the seller about it though.

Also, just noticed that 8833 cable has a female SCART input. Most switchboxes are configured for male inputs on both the inputs and outputs.... you'd need a gender changer to use it with a switchbox. (Or manually swap cables into the monitor cable's female SCART connector)

[smallfish]

An option that I considered was taping the RGB and Composite lines from each console and wiring them to 4 RCA jacks on the consoles exterior. Then, get RCA to BNC adapter dongles and just use a standard composite and component RCA cable for hooking it all up.