CGA/EGA/YUV to VGA converter & Amiga 1200

[RetroAmigaMan]

Hi

My 1084S is getting on in years, so I've bought an LCD PC monitor, a CGA/EGA/YUV to VGA converter board, and a decent 5V power supply.  I have 3 x Amiga to VGA converters for testing.  

I've read on the forum that there's little work involved other than maybe a little adjustment on the onboard POTs for colour. The board to the LCD monitor works perfectly, and I've selected an English-language menu.

Only problem is I can't get a stable picture from my A1200, in high-res NTSC or PAL.  All I get is a rolling display, which drops to a green screen.  Is there anything I can do, or have I scored a faulty board?

[Speelgoedmannetje]

High res output on the A1200 might as well be an actual VGA signal.

[amigadave]

Hi

My 1084S is getting on in years, so I've bought an LCD PC monitor, a CGA/EGA/YUV to VGA converter board, and a decent 5V power supply.  I have 3 x Amiga to VGA converters for testing.  

I've read on the forum that there's little work involved other than maybe a little adjustment on the onboard POTs for colour. The board to the LCD monitor works perfectly, and I've selected an English-language menu.

Only problem is I can't get a stable picture from my A1200, in high-res NTSC or PAL.  All I get is a rolling display, which drops to a green screen.  Is there anything I can do, or have I scored a faulty board?

Hard to help you when you don't provide specifics on which hardware you are using.  Which LCD monitor make and model number are you trying to use?  What Amiga to VGA converters are you trying to use?  What is this CGA/EGA/YUV to VGA converter you have purchased and how is it connected to your Amiga?

This is a very common thread topic and there are probably literally hundreds of threads and posts on this topic over the years that you could search through on this site and other Amiga websites.

[RetroAmigaMan]

Hard to help you when you don't provide specifics on which hardware you are using.  Which LCD monitor make and model number are you trying to use?  What Amiga to VGA converters are you trying to use?  What is this CGA/EGA/YUV to VGA converter you have purchased and how is it connected to your Amiga?

This is very common thread topic and there are probably literally hundreds of threads and posts on this topic over the years that you could search through on this site and other Amiga websites.

The Amiga RGB to VGA adaptors work perfectly - one is a brand new old stock Commodore model, the other two are after market.  The issue is with this:

http://www.ebay.com.au/itm/260839967494?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

The unit is very common for Arcade machine conversions, and I've seen it mentioned on the forum (I have searched other posts), but nothing specific has been said how to adapt it for the Amiga.  I'm running a VGA adaptor and a VGA lead straight into the VGA input on the board.  

I've actually seen posts around the net of a couple of Amiga users running a setup like mine, with no apparent modifications needed.

This is the same board used by an eBay seller, who has added a custom metal case.  I'd like to know how it was wired up, as it's been rigged up to run an Amiga 23pin cable straight off the board, and the Amiga supplies the 5V power.

The monitor I'm using is just a standard Dell LCD PC monitor, and works perfectly also.

Can anyone help? I'm suspecting I have a faulty board, but I'd like to know if anyone else has used a similar board....

[Daedalus]

There's nothing too unusual about the A1200 video output, so devices like this should work. Did you do the connecting yourself? It sounds like a sync signal issue to me - perhaps there are settings on the board regarding the sync signal. The Amiga by default provides horizontal and vertical sync signals on separate lines - perhaps the board is expecting composite sync, sync-on-green or some other system, in which case some minor modifications might be needed.

[buzz]

T
I've actually seen posts around the net of a couple of Amiga users running a setup like mine, with no apparent modifications needed.

You didn't check eab though right?

http://eab.abime.net/showpost.php?p=759262&postcount=16

[broken]

Anyone notice the jerky scrolling on a PAL machine? Looking at the specs on the GBS-8220, it appears it samples everything up to 60Hz and with PAL games and demo's it results in jerky scrolling. It does on my PAL 1200.

Also, appears that it doesn't truly support 24bit output as it dithers AGA output somewhat. This is really noticeable if you have a Copper WB backdrop like the one included with ClassicWB.


I can put up with the slight dithering, but the jerky ass scrolling is a deal breaker because it makes PAL games and demo's craptastic.

I used my GBS-8220 for all of 30 minutes then boxed it back up.

Disappointed.

[RetroAmigaMan]

Guys - thanks for your help.  The links are fantastic.  I'll have a go at wiring up the board directly.  Might still go with trying to get a hold of a small LCD TV with a SCART input though.  My 1084S is still in good nick, but I wouldn't want to not have a backup.

Have a great Christmas.

[RetroAmigaMan]

Thanks to Johnim from EAB - I've just done a little soldering with an old Amiga RGB to VGA adaptor.  The board works perfectly.  Certainly well enough for most games!

Have a great Christmas & New Year.

Thanks again for all your help.

Steve

[johnim]

glad you got it sorted