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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: sperrett on February 27, 2011, 09:01:42 PM

Title: RGB to VGA adaptor
Post by: sperrett on February 27, 2011, 09:01:42 PM
Hi Guys! I'm new here and signed up having just rescued my old A1200 from a pile of dust in the Attic! :) I used to have a lovely Multiscan monitor that I bought from David Pleasance. (http://www.amigahistory.co.uk/people/pleasance.jpg) Managing Director of Commadore UK. Sadly! It's now dead! So I've been trying to find an alternative. I have a 17" CRT monitor and I was wondering if this (http://cgi.ebay.co.uk/RGBs-EGA-CGA-YUV-15K-2-VGA-31K-Signal-Converter-PCB-/190503837370?pt=UK_VideoGames_VideoGameAccessories_VideoGameAccessories_JN&hash=item2c5ae9deba) would work? What d'you think?
Title: Re: RGB to VGA adaptor
Post by: SamuraiCrow on February 27, 2011, 09:10:39 PM
I think your second link is broken.  But whether or not an RGB to VGA adapter will work well depends on the monitor you're hooking it to.  If you have an ordinary VGA monitor it will require a scan doubler such as the IndivisionAGA which will be coming out with a new batch shortly.  Otherwise you'll be stuck with using the AGA mode promotion which doesn't work well even if it does work.
Title: Re: RGB to VGA adaptor
Post by: drHirudo on February 27, 2011, 09:21:53 PM
You can use RGB to SCART convertor and use monitor with use input. I use such LG monitor and the pictures is very good. Much better than from the composite out almost RGB quality.
Title: Re: RGB to VGA adaptor
Post by: sperrett on February 27, 2011, 09:51:05 PM
The link is to this. It costs £18 I would imagine that's about $25...?
(http://i.ebayimg.com/00/$%28KGrHqQOKiYE1fLj12ytBN%289,YSSdw%7E%7E_35.JPG)
Please wait
Image not available






(http://q.ebaystatic.com/aw/pics/s.gif)

 RGBs EGA CGA YUV 15K to 2 VGA 31K Signal Converter PCB
Title: Re: RGB to VGA adaptor
Post by: XDelusion on February 27, 2011, 10:01:31 PM
Here's a couple of options to consider:

http://www.amigamaniac.com/RGB_to_PAL_NTSC_adapter.html


http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=918
Title: Re: RGB to VGA adaptor
Post by: sperrett on February 27, 2011, 10:10:02 PM
Quote from: XDelusion;618296
Here's a couple of options to consider:

http://www.amigamaniac.com/RGB_to_PAL_NTSC_adapter.html


http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=918

The scan doubler is £85. I can't justify spending that amount on my Amiga. As much as I love it!  I might try the option I've posted. If it works! It wont take much to encase it. And at £18, it will be worth it! It says clearly that it converts 15k to (2x) 31k. I'll let you all know if it works!
Title: Re: RGB to VGA adaptor
Post by: ribdevil1 on February 27, 2011, 10:13:28 PM
In theory, yes, it doubles de RGB 15k from the Amiga to VGA 31k, so any VGA monitor works, but I can't see very well the connectors, I think you need and extra adaptor from the RGB Amiga to the RGB input of the converter.
Title: Re: RGB to VGA adaptor
Post by: XDelusion on February 27, 2011, 10:16:19 PM
Quote from: sperrett;618297
The scan doubler is £85. I can't justify spending that amount on my Amiga. As much as I love it!  I might try the option I've posted. If it works! It wont take much to encase it. And at £18, it will be worth it! It says clearly that it converts 15k to (2x) 31k. I'll let you all know if it works!


If that works for you, lemme me know, I'm very curious!
Title: Re: RGB to VGA adaptor
Post by: sperrett on February 27, 2011, 10:19:14 PM
Quote from: SamuraiCrow;618278
I think your second link is broken. .

Just fixed it if you wanna look?
Title: Re: RGB to VGA adaptor
Post by: abruzzi on February 27, 2011, 10:30:03 PM
I plugged my Amiga 3000 (with the scan doubler disabled) into my Acer LCD monitor (20', $100) and it worked just fine.  Since a lot of new LCD monitors were probably specced in the factory to do double duty as monitors or TVs, many may work.  Mine works fine with HiRes and others, it just doesn't like PAL modes.

Geof
Title: Re: RGB to VGA adaptor
Post by: desantii on February 27, 2011, 11:43:18 PM
I bought one of these some weeks ago. Works.. somewhat
 
It does scandouble so you get a nice display with no flicker and high res, but after a while it starts getting funny, like it looses sync and the image is wavy. I am travelling but will post a pic when I get back
 
Quote from: sperrett;618294
The link is to this. It costs £18 I would imagine that's about $25...?
(http://i.ebayimg.com/00/$%28KGrHqQOKiYE1fLj12ytBN%289,YSSdw%7E%7E_35.JPG)
Please wait
Image not available
 
 

  • Enlarge

 
(http://q.ebaystatic.com/aw/pics/s.gif)
 
RGBs EGA CGA YUV 15K to 2 VGA 31K Signal Converter PCB
Title: Re: RGB to VGA adaptor
Post by: alexh on February 27, 2011, 11:55:27 PM
Quote from: desantii;618315
after a while it starts getting funny, like it looses sync and the image is wavy.

Is this an 1.D4 A1200? Perhaps you need to add a capacitor to the circuit recently identified in another post?

http://www.amiga.org/forums/showpost.php?p=611485&postcount=17

http://aminet.net/package/docs/hard/flickfix
Title: Re: RGB to VGA adaptor
Post by: desantii on February 27, 2011, 11:57:35 PM
I was trying the adaptor in an A2000 using an origibal 23-9 pin cable to feed the adaptor. First i used a 23-25 adaptor to feed to the 15pin port and it did not owrk.
 
Then I used the 23-9 cable and took the signal from that
Title: Re: RGB to VGA adaptor
Post by: Stedy on February 28, 2011, 12:09:10 AM
Sperret, that looks like the Gongbes unit, commonly sold on ebay. Here are the tech specs, sorry about the formatting, the website is down, this is taken from my Onenote book.

GONGBES
8220
The high definition converter GBS-8220 is a professional game& playstation display converter. Supported all games(Amusement. Play statioft Xbox. wii )convert to CRT monitors LCD monitor PDP monitor Auto scan CGA1EGAIYUV signal, VGA outputs, output high resolution signal.
Power
DC5V 2A ±1- 0.5v
P7 or P9
Input
signal
CGA/EGA
14.5-16.5K
23.5-25.5K
30.5-32.5K Auto scan P3 or P11 or PlO
RGBHV  30.5-32.5K  Auto scan PlO or P11
VGA
30.5-32.5K Auto scan PlO or P11
Ypbpr  
480p, 576p,720p, 1080p Auto scan P2
Ycbcr
480i,576i,720i, 1080i Auto scan P2
Output signal
VGA
640*480,800*600
1024*768,1360*768
P4 and P13

User control
Input Switch, Image Zoom, Image Position,
Output Resolution ,R\G\B gain adjust.
Menu Key
R\G\B VR
Dimensions
115*105*20mm

The main issue is that it will not be able to process the RGB video from the Amiga. It accepts YPbPr/YCbCr video but this is a different colourspace (the picture may work but will have incorrect colours).

You will need one of these to colourspace convert:
http://www.jaycar.co.uk/productView.asp?ID=KC5398&keywords=video+converter&form=KEYWORD

Ian
Title: Re: RGB to VGA adaptor
Post by: sperrett on March 07, 2011, 07:51:15 PM
Interesting. Thanks Ian.
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 07, 2011, 08:06:55 PM
Quote from: XDelusion;618296
Here's a couple of options to consider:

http://www.amigamaniac.com/RGB_to_PAL_NTSC_adapter.html
Crippling a fine rgb signal, usable on most of the modern flatscreen tellies, to lousy s-video or even composite signal. What are you thinking?
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 07, 2011, 08:09:57 PM
Quote from: Stedy;618323
Sperret, that looks like the Gongbes unit, commonly sold on ebay. Here are the tech specs, sorry about the formatting, the website is down, this is taken from my Onenote book.

GONGBES
8220
The high definition converter GBS-8220 is a professional game& playstation display converter. Supported all games(Amusement. Play statioft Xbox. wii )convert to CRT monitors LCD monitor PDP monitor Auto scan CGA1EGAIYUV signal, VGA outputs, output high resolution signal.
Power
DC5V 2A ±1- 0.5v
P7 or P9
Input
signal
CGA/EGA
14.5-16.5K
23.5-25.5K
30.5-32.5K Auto scan P3 or P11 or PlO
RGBHV  30.5-32.5K  Auto scan PlO or P11
VGA
30.5-32.5K Auto scan PlO or P11
Ypbpr  
480p, 576p,720p, 1080p Auto scan P2
Ycbcr
480i,576i,720i, 1080i Auto scan P2
Output signal
VGA
640*480,800*600
1024*768,1360*768
P4 and P13

User control
Input Switch, Image Zoom, Image Position,
Output Resolution ,R\G\B gain adjust.
Menu Key
R\G\B VR
Dimensions
115*105*20mm

The main issue is that it will not be able to process the RGB video from the Amiga. It accepts YPbPr/YCbCr video but this is a different colourspace (the picture may work but will have incorrect colours).

You will need one of these to colourspace convert:
http://www.jaycar.co.uk/productView.asp?ID=KC5398&keywords=video+converter&form=KEYWORD

Ian

As I see there, it can handle CGA signals, and that's the same as the RGBs signal on the Amiga. It'll work just fine.
Title: Re: RGB to VGA adaptor
Post by: alexh on March 07, 2011, 08:17:02 PM
Quote from: Speelgoedmannetje;620221
it can handle CGA signals, and that's the same as the RGBs signal on the Amiga. It'll work just fine.

CGA is RGBI and not the same as the Amiga's RGBs output! CGA is a digital output and Amiga RGBs is analog.

http://en.wikipedia.org/wiki/Color_Graphics_Adapter

9/10 times when it says "CGA->VGA adapter" it is a mistake. They actually mean analog "RGBs->VGA adapter".
Title: Re: RGB to VGA adaptor
Post by: mongo on March 07, 2011, 08:28:51 PM
Quote from: Stedy;618323
You will need one of these to colourspace convert:
http://www.jaycar.co.uk/productView.asp?ID=KC5398&keywords=video+converter&form=KEYWORD


There's no sync inputs on that. I assume that it uses sync on green, but that's not very useful for an Amiga.
Title: Re: RGB to VGA adaptor
Post by: broken on March 07, 2011, 08:31:32 PM
Quote from: Speelgoedmannetje;620220
Crippling a fine rgb signal, usable on most of the modern flatscreen tellies, to lousy s-video or even composite signal. What are you thinking?


Not everyone lives in Europe with an RGB Scart capable TV.
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 07, 2011, 08:44:26 PM
Quote from: alexh;620223
CGA is RGBI and not the same as the Amiga's RGBs output! CGA is a digital output and Amiga RGBs is analog.

http://en.wikipedia.org/wiki/Color_Graphics_Adapter

9/10 times when it says "CGA->VGA adapter" it is a mistake. They actually mean analog "RGBs->VGA adapter".
That's what I thought as well, but I've seen often CGA regarded as a 15khz RGBs signal.
If we take a closer look:
(http://www.arcademvs.com/accesseriors/2vga.jpg)
Clearly, RGBs is stated on the left bottom of the picture.
Title: Re: RGB to VGA adaptor
Post by: Zac67 on March 07, 2011, 08:46:54 PM
Quote from: Speelgoedmannetje;620227
That's what I thought as well, but I've seen often CGA regarded as a 15khz RGBs signal.


Well, it's 15 kHz all right, and it's got RGB but it's 4 bit digital only (R, G, B & I), so all you get is those lousy 16 colors. Yuck.
(http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/CGA-NTSC-colors.png/220px-CGA-NTSC-colors.png)
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 07, 2011, 08:48:30 PM
Quote from: Zac67;620228
Well, it's 15 kHz all right, and it's got RGB but it's 4 bit digital only (R, G, B & I), so all you get is those lousy 16 colors. Yuck.

I know I wrote the s of RGBs in lower case, but surely, it was there clear enough.
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 07, 2011, 09:01:59 PM
Quote from: broken;620225
Not everyone lives in Europe with an RGB Scart capable TV.
There's a big chance the VGA input of a flatscreen tv can also handle the 15khz signals as it is most likely the very same chip the EU SCART connectors are connected to.
Title: Re: RGB to VGA adaptor
Post by: broken on March 07, 2011, 11:55:33 PM
Quote from: Speelgoedmannetje;620232
There's a big chance the VGA input of a flatscreen tv can also handle the 15khz signals as it is most likely the very same chip the EU SCART connectors are connected to.


Not here in North America there isn't.

I can't think of a single flatscreen TV that is sold here in the US that can take 15khz over VGA. Sure, there are some multisystem flatpanels that are sold by specialty stores, but they are stupid expensive as they are not mainstream. You can't wonder into a retail store and buy these...mostly just order over the 'Net. They are probably imported from the UK anyways.

However many of the inexpensive LCDs do sync to 50Hz PAL signals over composite/s-video or component. I own 2 Vizio sets that both do...a 26 inch and 47 inch. But if you buy a big name model - Sony, Toshiba, Panasonic and etc, there is just about ZERO percent chance they will sync to 50Hz sadly.
Title: Re: RGB to VGA adaptor
Post by: NovaCoder on March 08, 2011, 12:13:09 AM
Quote from: sperrett;618276
Hi Guys! I'm new here and signed up having just rescued my old A1200 from a pile of dust in the Attic! :) I used to have a lovely Multiscan monitor that I bought from David Pleasance. (http://www.amigahistory.co.uk/people/pleasance.jpg) Managing Director of Commadore UK. Sadly! It's now dead! So I've been trying to find an alternative. I have a 17" CRT monitor and I was wondering if this (http://cgi.ebay.co.uk/RGBs-EGA-CGA-YUV-15K-2-VGA-31K-Signal-Converter-PCB-/190503837370?pt=UK_VideoGames_VideoGameAccessories_VideoGameAccessories_JN&hash=item2c5ae9deba) would work? What d'you think?



Just go with a simple (cheap RGB-to-VGA) adapter and run MultiSync + VGA Only which will work for WB and games that support it (like mine for example).

When the IndivisionAGA Mrk2 comes out then just wack one in there and you'll be able happy.

Easy :)
Title: Re: RGB to VGA adaptor
Post by: sperrett on March 20, 2011, 09:57:46 AM
OK. Tried it and it doesn't work! It almost works in that, I can see the the workbench screen intermitantly! And I'm sure somebody a lot more savvy than I could probably tweak it to work!  Ah well! Back to the TV. :)
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 20, 2011, 10:27:40 AM
Quote from: sperrett;623247
OK. Tried it and it doesn't work! It almost works in that, I can see the the workbench screen intermitantly! And I'm sure somebody a lot more savvy than I could probably tweak it to work!  Ah well! Back to the TV. :)
You can get the menu overlay of the converter? Probably it's set to ypbpr, or it is set to NTSC (or PAL and you live in an NTSC-using country).
Title: Re: RGB to VGA adaptor
Post by: sperrett on March 20, 2011, 02:08:26 PM
Quote from: Speelgoedmannetje;623249
You can get the menu overlay of the converter? Probably it's set to ypbpr, or it is set to NTSC (or PAL and you live in an NTSC-using country).

I have tried all possible modes from the menu.
Title: Re: RGB to VGA adaptor
Post by: Speelgoedmannetje on March 20, 2011, 03:34:36 PM
Quote from: sperrett;623265
I have tried all possible modes from the menu.

Hmok, on which input part did you attach it?
Title: Re: RGB to VGA adaptor
Post by: sperrett on March 20, 2011, 04:17:31 PM
Quote from: Speelgoedmannetje;623275
Hmok, on which input part did you attach it?
RGBhv input. I have no other connectors to try it.
Title: Re: RGB to VGA adaptor
Post by: Stedy on March 21, 2011, 12:20:17 AM
Take a look at the updated website page here:
http://www.gonbes.com/en/product_detail.asp?menuid=95&id=23

The Amiga's video output is around 15 KHz horizontal scan rate. The only matching video mode listed directly is CGA/EGA. If you were to connect the Digital RGB pins (pins 7-9) and the digital intensity (pin 6)  of the Amiga to this adaptor via the P10 or P11 or RGBHV 15 way d-type, you will get an image but only in 16 colours.

The only other way to utilise this adaptor is to take the RGB output, use an Analogue RGB to YCbCr/YPbPr/YUV colour space converter and add an attenuated TTL CSYNC signal from the Amiga, to the Y video output. You could then use the 480i (NTSC) or 576i (PAL) modes that this device supports.

There is an Amiga RGB to component/YUV video adaptor currently in development, not by myself but I am aware of it and reviewed the design, that could be used with this interface adaptor.

Ian
Title: Re: RGB to VGA adaptor
Post by: desantii on March 21, 2011, 01:22:52 AM
I was able to get this working, but only for a while. After a while it looses sync and there is like a wave moving vertically. Before that happens it actually works great. See some screenshots of a high res workbench screen, the bottom one shows how the image gets distorted after a while.   I coonnected using a 23-9 Amiga cable and then bought a 9pin female to plug in
 
(http://i419.photobucket.com/albums/pp278/desantii/DSC00181.jpg)
(http://i419.photobucket.com/albums/pp278/desantii/DSC00183.jpg)
(http://i419.photobucket.com/albums/pp278/desantii/DSC00184.jpg)
 
(http://i419.photobucket.com/albums/pp278/desantii/DSC00185.jpg)