View topic - Game Gear dev hardware - Scart output via. Krisalis Gear Decoder

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Forum Index Main Game Gear dev hardware - Scart output via. Krisalis Gear Decoder

Author	Message
radar Joined: 22 Jun 2005 Posts: 10 Location: New Zealand	Game Gear dev hardware - Scart output via. Krisalis Gear Decoder Posted: Sat Mar 24, 2018 8:35 am
	A few years ago I posted about and got the Rom dumped for a nice bit of Sega Dev hardware - a Krisalis Dev box. http://www.smspower.org/forums/15019-KrisalisSoftwareSMSGGDevBox#82986 The same source (ex-Virgin Interactive skip/dumpster) recently found another box of long stored goodies that contained another dev unit that also uses at its heart a Krisalis "Gear Decoder board". This one just appears to provide a Scart RGB output method for testing / demo purposes. Not pretty but still neat to see early ingenuity. Unfortunately it doesn't appear to be working so I can't provide a demo of it running at this stage. IMG_20180324_170814.jpg (1.86 MB) IMG_20180324_170853.jpg (1.85 MB) IMG_20180324_170948.jpg (1.07 MB) IMG_20180324_171118.jpg (1.46 MB) IMG_20180324_171133.jpg (1016 KB)
segasonicfan Joined: 05 Jan 2006 Posts: 374 Location: USA	Posted: Sun Mar 25, 2018 2:21 am
	wow, that is incredibly cool. I can't believe someone reverse engineered it so long ago! They must've seen the official Sega board. I've been following this mod since Xavier's thread here way back in 2007. I've built a number of them by hand and I provided some early schematics as well. Shoot me a message if you want to work something out for me to repair this. It would be a neat project and a worthy museum piece. -Segasonicfan
radar Joined: 22 Jun 2005 Posts: 10 Location: New Zealand	Posted: Sun Mar 25, 2018 7:15 pm
	Some good news, it lives! Yesterday I managed to fix the unit and can confirm it works. A couple of simple issues, a broken power wire (the "box" is powered (9V) via. a connection directly to the PSU plug inside the GG) and there was a wire broken off at the pin in the Scart connector. Attached are a photo of the terminations inside the GG and some quick screenshots of it running. The version of Dragon shown is running off a 171-5986B Dev board. The pot on the "box" alters the colour output and needs to be tweaked to bring them as close as possible to the right pallet. IMG_20180325_201210.jpg (1.53 MB) IMG_20180325_204603.jpg (1.1 MB) IMG_20180325_204956.jpg (1.45 MB) IMG_20180325_205130.jpg (1.65 MB)
ccovell Joined: 26 Dec 2004 Posts: 374 Location: Japan	Posted: Wed Mar 28, 2018 11:14 am
	The board looks really close to Xavier's schematic from over 10 years ago too. Nostalgic stuff.

Forum Index Main Game Gear dev hardware - Scart output via. Krisalis Gear Decoder