Digital signals on Amiga video connector

whitebird · 25 September 2010, 23:17

Hello,

I need some information about the DR, DG, DB, DI signals located respectively on pins 9, 8, 7, 6 of RGB connector.

I am sorry if it has already been disussed.

What I understand from schematics is that DR, DG, DB corresponds to the MSB of each of the 8 bits of each color. DI is B4, so those 4 signals can generate only 16 colors.

What are DR, DG, DB, DI used for.

Fabie · 26 September 2010, 08:55

Quote:

Originally Posted by whitebird

Hello,

I need some information about the DR, DG, DB, DI signals located respectively on pins 9, 8, 7, 6 of RGB connector.

I am sorry if it has already been disussed.

What I understand from schematics is that DR, DG, DB corresponds to the MSB of each of the 8 bits of each color. DI is B4, so those 4 signals can generate only 16 colors.

What are DR, DG, DB, DI used for.

it seems that those signals were made to connect a CGA monitor
you can connect one if you want...but will work only in 16 colors I think

meega · 26 September 2010, 09:04

They are TTL (transistor-transistor logic) signals, output is 5V iirc, and they switch the appropriate colour gun on/off - no intermediate levels. You can have Red, Green, Blue, Yellow (Red+Green), Magenta (Red+Blue), Cyan (Green+Blue), White (all on), Black (all off), and that is all eight of the colours. The DI is digital Intensity (brightness), so you do get half levels too (hence 16 total, although "half-black" makes no real sense so it's 15 distinct shades) as long as your monitor can accept that input.

whitebird · 26 September 2010, 09:30

Thanks.

But I think this way of working requests an image to be adapted. Because if all 3 colors are bellow 127 for all the pixels on screen, the picture would be completely black.

meega · 26 September 2010, 09:37

Think BBC micro, CeeFax/Teletext, etc. Thirty years ago, any colour at all was advanced stuff.

alexh · 26 September 2010, 10:08

It is a standard 16-colour TTL digital output. Think CGA. Can work with some monitors such as CUB & Philips but why would you want to with only 16-colours?

pandy71 · 26 September 2010, 11:42

They are used by A2024, Graffiti board, i assume also by DCTV and probably by other video hardware to.

whitebird · 26 September 2010, 15:34

Quote:

but why would you want to with only 16-colours

Nothing, I was just wondering what are those signal for...

25 September 2010, 23:17	#1
whitebird Registered User Join Date: May 2006 Location: France Age: 48 Posts: 211	Digital signals on Amiga video connector Hello, I need some information about the DR, DG, DB, DI signals located respectively on pins 9, 8, 7, 6 of RGB connector. I am sorry if it has already been disussed. What I understand from schematics is that DR, DG, DB corresponds to the MSB of each of the 8 bits of each color. DI is B4, so those 4 signals can generate only 16 colors. What are DR, DG, DB, DI used for.

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26 September 2010, 09:04	#3
meega Registered User Join Date: Dec 2007 Location: Oooh what a feeling yeaaah dancing on the ceiling Posts: 314	They are TTL (transistor-transistor logic) signals, output is 5V iirc, and they switch the appropriate colour gun on/off - no intermediate levels. You can have Red, Green, Blue, Yellow (Red+Green), Magenta (Red+Blue), Cyan (Green+Blue), White (all on), Black (all off), and that is all eight of the colours. The DI is digital Intensity (brightness), so you do get half levels too (hence 16 total, although "half-black" makes no real sense so it's 15 distinct shades) as long as your monitor can accept that input.

26 September 2010, 09:30	#4
whitebird Registered User Join Date: May 2006 Location: France Age: 48 Posts: 211	Thanks. But I think this way of working requests an image to be adapted. Because if all 3 colors are bellow 127 for all the pixels on screen, the picture would be completely black.

26 September 2010, 09:37	#5
meega Registered User Join Date: Dec 2007 Location: Oooh what a feeling yeaaah dancing on the ceiling Posts: 314	Think BBC micro, CeeFax/Teletext, etc. Thirty years ago, any colour at all was advanced stuff.

26 September 2010, 10:08	#6
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,331	It is a standard 16-colour TTL digital output. Think CGA. Can work with some monitors such as CUB & Philips but why would you want to with only 16-colours?

26 September 2010, 11:42	#7
pandy71 Registered User Join Date: Jun 2010 Location: PL? Posts: 2,741	They are used by A2024, Graffiti board, i assume also by DCTV and probably by other video hardware to.

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