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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: TheBilgeRat on February 28, 2011, 07:48:22 PM

Title: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on February 28, 2011, 07:48:22 PM

Anybody have the pinouts for a 23 pin RGB to 15 pin VGA adaptor?  I'd like to do a DIY since I have the pieces parts.

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Franko on February 28, 2011, 07:54:53 PM

Quote from: TheBilgeRat;618481

Anybody have the pinouts for a 23 pin RGB to 15 pin VGA adaptor?  I'd like to do a DIY since I have the pieces parts.

Yes... :)

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on February 28, 2011, 08:05:10 PM

Quote from: Franko;618485

Yes... :)

Care to share it? :D

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Franko on February 28, 2011, 08:06:16 PM

Quote from: TheBilgeRat;618487

Care to share it? :D

Maybe... :)

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: AndyFC on February 28, 2011, 08:09:47 PM

The Amiga RGB pin out is here: http://www.ntrautanen.fi/computers/hardware/misc/amiga_rgb.htm
VGA pin out here: http://www.l-com.com/content/Audio-Video-Tutorial.html

I built one and linked the RGBs, the H and V syncs and a ground.

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on February 28, 2011, 08:13:43 PM

Quote from: AndyFC;618490

The Amiga RGB pin out is here: http://www.ntrautanen.fi/computers/hardware/misc/amiga_rgb.htm
VGA pin out here: http://www.l-com.com/content/Audio-Video-Tutorial.html

I built one and linked the RGBs, the H and V syncs and a ground.

the analog or digital RGB?  Also, that link suggested that modern monitors want something on the 15 pin.  VGA pinout says its a data clock... Wonder if pin 1 on amiga 23pin and pin 15 VGA would be happy together...

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Franko on February 28, 2011, 08:17:33 PM

While I don't have a proper schematic (only a hand drawn one I did years ago), here's the links to the appropriate pinouts, just remember of course that the monitor your using will have to be able to sync down to proper PAL/NTSC refresh rates 15/16Khz... :)

Amiga Video Port PinOut... (http://pinouts.ru/Video/AmigaVideo_pinout.shtml)

VGA Connector PinOut... (http://pinouts.ru/Video/VGA15_pinout.shtml)

(oops... AndyFC beat me to this one... :))

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Franko on February 28, 2011, 08:23:09 PM

Quote from: TheBilgeRat;618492

the analog or digital RGB?  Also, that link suggested that modern monitors want something on the 15 pin.  VGA pinout says its a data clock... Wonder if pin 1 on amiga 23pin and pin 15 VGA would be happy together...

Analog of course unless you're monitors digital only...

Never needed to use pin 15 on any old monitors I've tried before, just been a straight forward pin for pin connection... :)

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Zac67 on February 28, 2011, 08:28:13 PM

Quote from: TheBilgeRat;618492

the analog or digital RGB?

Forget digital RGBI - that's CGA compatible with the same terrific colors.
With VGA the PC went analogue as well (until DVI/HDMI/DP/DiiVA surfaced).

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on March 01, 2011, 12:06:02 AM

sweetness - +5V, gnd, R, G, B it is, then! :D

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: mongo on March 01, 2011, 12:19:42 AM

Quote from: TheBilgeRat;618541

sweetness - +5V, gnd, R, G, B it is, then! :D

R, G, B, VSYNC, HSYNC, and GND.

No +5V.

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Louis Dias on March 01, 2011, 02:05:48 AM

I find this site quite informative:
http://pinouts.ru/

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on March 01, 2011, 06:20:22 AM

Quote from: mongo;618543

R, G, B, VSYNC, HSYNC, and GND.

No +5V.

Yikes!  my bad - will rock it proper.

I'm still at "pulling the really stuck 23-pin terminals out of the ancient plastic block" phase of the operation.

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Zac67 on March 01, 2011, 07:25:02 AM

Some CRTs reportedly load the sync signals too heavily. If Miggy fails to boot up, don't be alarmed - you'll need to add serial resistors or add a transistor for signal boost.

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: Daedalus on March 01, 2011, 08:47:22 AM

The data connections shouldn't be *required* by a modern monitor, and Amigas can't read them on the RGB connector anyway. The main reason for a data connection is monitor->PC communication about monitor capabilities, the monitor gets all the information it needs about the picture from the sync signals.

I think there are a few diagrams on Aminet in hard/docs or hard/hacks which show how to make a simple connector, and a simple buffered one using a transistor, resistor and the +5V from the Amiga. I'll rummage around at home and see if I can find it...

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on May 14, 2013, 03:58:18 PM

Quote from: Zac67;618581

Some CRTs reportedly load the sync signals too heavily. If Miggy fails to boot up, don't be alarmed - you'll need to add serial resistors or add a transistor for signal boost.

I just got an Idek 17" that is probably doing this right here - All I get is flashing green power light with it attached.  would I put resistance on both sync lines?  If so how much?

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on May 14, 2013, 05:03:12 PM

So, after a bit of research I came across this link for anyone else in my predicament and who wants to build this thing on their own:

http://amigadev.elowar.com/read/ADCD_2.1/AmigaMail_Vol2_guide/node015E.html

It looks like the original Commodore converters used a 74HCT08 as the intermediary in the Hsync/Vsync side and powered it off the +5 on the amiga side.

Of course, you could always buy it from Amigakit :lol:

But I've come too far already!  Damn the torpedoes!

Title: Re: Pinout on 23 pin RGB to 15 pin VGA?
Post by: TheBilgeRat on May 14, 2013, 05:09:21 PM

In fact, just in case amiga.org outlives that site, here is the diagram and its info:

A1-A14 are pins 1 - 14 on 74HCT08.
C1 is a .01uf 50A ceramic capacitor.