Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: sed6 on September 23, 2012, 11:56:44 pm

Title: Help with CGA to VGA for Galaga
Post by: sed6 on September 23, 2012, 11:56:44 pm
I'm trying to use this converter to play Galaga on my Samsung LCD TV via it's PC IN input.  When hooked up as shown all I get on the TV screen is "check signal input"  Can anyone help with this?

(http://inlinethumb62.webshots.com/50685/2017536370048482531S600x600Q85.jpg)

-Scott
OKC, OK
Title: Re: Help with CGA to VGA for Galaga
Post by: MonMotha on September 24, 2012, 12:01:15 am
Do you have any documentation on this thing?  I don't see a scaler on there (it could be on the bottom), so it may just be a signal level converter.  Most TVs don't accept 15kHz timings on their VGA inputs for some reason.
Title: Re: Help with CGA to VGA for Galaga
Post by: sed6 on September 24, 2012, 09:24:52 am
No documents and the bottom side is just PCP traces. Would a computer monitor be more likely to work?
Title: Re: Help with CGA to VGA for Galaga
Post by: MonMotha on September 24, 2012, 09:28:14 am
PC monitors usually have the same limitation as TVs.

Are you even sure it's designed use the "arcade" side as an input and the "VGA" side as an output?  The other way looks more probable.  The circuit looks like it probably implements a basic video amp.
Title: Re: Help with CGA to VGA for Galaga
Post by: adder on September 24, 2012, 05:35:04 pm
what is it/where did u get it?
 no clues on it to the company who made it? (what's that word say on it, THUNDEM?)
Title: Re: Help with CGA to VGA for Galaga
Post by: sed6 on September 25, 2012, 09:11:58 am
I borrowed from a guy locally. I checked with him last night and he suspects my TV and computer monitor are too new to process the signal. He tells me it converts the wires but not the frequency and most new displays don't work with 15hz signals, hence the need for a really old monitor or tube. Or something like that. I'm going to take my whole game to his place tomorrow and see if we can get it working.
Title: Re: Help with CGA to VGA for Galaga
Post by: MonMotha on September 25, 2012, 04:58:35 pm
PC monitors capable of 15k haven't been common since the early 90s, so yeah, basically everything you have is probably "too new".  Some professional/commercial monitors in large format (big tubes, plasma, LCD, etc.) will do it, but generally the consumer models won't for some reason (not like it's hard...I suspect it may just be disabled for market segmentation, same as dual mode PAL/NTSC support on modern digital monitors).
Title: Re: Help with CGA to VGA for Galaga
Post by: mgb on September 25, 2012, 11:52:36 pm
try a converter like this. They're fairly cheap.
http://www.jammaparts.net/vga-converters/45-rgb-cga-to-vga-.html (http://www.jammaparts.net/vga-converters/45-rgb-cga-to-vga-.html)
Title: Re: Help with CGA to VGA for Galaga
Post by: astroone on October 10, 2012, 12:17:44 am
I agree with mgb I got a Donkey Kong working with one of these I did notice the site mgb sent you to is sold out here's another one
http://www.amazon.com/SainSmart-GBS-8220-Arcade-Video-Converter/dp/B0051SLJAG (http://www.amazon.com/SainSmart-GBS-8220-Arcade-Video-Converter/dp/B0051SLJAG)

Extra Info on the Converter
http://www.jammaboards.com/faq/article/cga-to-vga-video-converter-gbs-8220-pcb-basic-setup-13.html (http://www.jammaboards.com/faq/article/cga-to-vga-video-converter-gbs-8220-pcb-basic-setup-13.html)

And here's some info on the Galaga Pinout
http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=pinout&page=Galaga.html (http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=pinout&page=Galaga.html)