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Old 26 September 2010, 00:17   #1
whitebird
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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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Old 26 September 2010, 09:55   #2
Fabie
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Quote:
Originally Posted by whitebird View Post
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
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Old 26 September 2010, 10:04   #3
meega
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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.
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Old 26 September 2010, 10:30   #4
whitebird
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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.
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Old 26 September 2010, 10:37   #5
meega
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Think BBC micro, CeeFax/Teletext, etc. Thirty years ago, any colour at all was advanced stuff.
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Old 26 September 2010, 11:08   #6
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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?
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Old 26 September 2010, 12:42   #7
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They are used by A2024, Graffiti board, i assume also by DCTV and probably by other video hardware to.
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Old 26 September 2010, 16:34   #8
whitebird
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Quote:
but why would you want to with only 16-colours
Nothing, I was just wondering what are those signal for...
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