My Sony MSX2+ has a DIN 8pin female connector for RGB output. How do I make it output to s-video instead?

Here's the pinout diagram at MSX FAQ - http://www.faq.msxnet.org/connector.html#rgbjap

AFAIK you can't. The s-video uses chrominance and luminance signals that are not present in the RGB connector. I'm not an electronics guru; but probably there're ways to convert the RGB signal into s-video. Your best move would be to buy an RGB monitor like the ones in the well known commodore series (1084/S with 9 pin video sub-d connector).

Why s-video?
You can adapt this RGB to a Scart, so you can connect it to a TV. I think it's easier.

He lives in the US, so his monitor/tv probably doesn't have a scart connection.

Ah! then, it's clear...

I recommend Micomsoft XAV-2S. It produces excellent results, because it uses one of the best video encoder: Sony CXA2075. The unit is very small, so it is easy to hide somewhere behind TV. I got mine about 3 years ago from NFGMan, before he moved from Japan to Australia.

Alternatively, you can use RGB out directly with Commodore 1084 monitor. I got mine from Goodwills for a very cheap price, and it works really well. All it took to get it working is a custom DIN-8 to DIN-6 + RCA for audio cable.

Hmm...that XAV-2S looks like the best choice and it's within my price range. But it seems like the only places selling them are in japan. You know of any distributors outside japan where I can buy it?

May be Mr. Ikeda can help you, he is incredibly friendly and helpful to us, non-japanese MSX freaks

Another alternative you may consider, is to ask Ronnie (rklok here) to import a Panasonic WX or WSX for you. He used to sell them for about 75 euro, and those are the nicest MSX computers, I like my WSX even more then my TurboR GT. They can easily be expanded to 512k, have internal S-Video, have a special 1.5X turbo mode that can be enabled by two port out commands. Also they have internal FM-PAC and floppy drive, floppy drive can be easily swapped for a normal PC floppy.

Thanks dhau. I'll try emailing Ronnie since I've purchased from him in the past. Maybe he can hook me up with a XAV-2s.

I used to have an RGB to S-Video (NTSC) encoder that I bought from jrok.com

There's also a cheaper DIY kit you can buy here http://www.neobitz.com/Pages/Mods/SystemMods.aspx

DamageX, did you have the version of JROK with component input? If yes, how well did it perform?

It was RGB input, S-video output. I used it with my Amiga, and the resolution was very good. When I connected it to a TV-tuner card in my PC the display was almost as sharp as connecting the Amiga directly to the VGA monitor (at 720x480 resolution)