Author Topic: CGA Monitors (Read 2432 times)

phreak97 · « **on:** April 16, 2005, 02:59:48 pm »

i've been offered a 21" CGA monitor, and a little googling told be cga uses ~15khz H-sync like a tv does.. but cga seems to want a pin for intensity.. so can i use it for rgb from consoles, or not?
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i have the monitor here now, it could even be a black and white monitor.. but i cant be sure.. the problem is that the 9 pin connector on the back has enough pins for rgb, (6) but theyre not positioned to fit any of the 9 pin monitor pinouts in the HardwareBook on gamesx.. i was told it is cga, but i think he just assumed that after seeing it was a 9 pin connector.
annyway, heres the pic of the connector on the back, i hope someone can shed some light as to what pinout to use.
pic:
Monitor Input + Model Number

yup, its black and white.. but i'd still like the pinout

benzaldehyde · « **Reply #1 on:** April 16, 2005, 07:50:59 pm »

Well, what you have there is an RGB monitor, but it uses that pesky digital signal format. The intensity pin is usually a dead giveaway. I once thought one would work too, and pretty much learned my lesson. Thusly, I'd pass up on it.

When looking, check for any mention of analog or linear RGB. That usually means it's the kind we like.

phreak97 · « **Reply #2 on:** April 16, 2005, 09:49:18 pm »

well.. it's not rgb, it's a monochrome monitor.. i said that at the bottom of my post.. but its probably still some similar format, still with the intensity pin.. so that sucks..

Endymion · « **Reply #3 on:** April 17, 2005, 11:44:41 am »

Quote

well.. it's not rgb, it's a monochrome monitor.. i said that at the bottom of my post..

Should've been a dead giveaway to you that it was digital, ergo incompatible.

benzaldehyde · « **Reply #4 on:** April 17, 2005, 01:44:16 pm »

Quote

well.. it's not rgb, it's a monochrome monitor.. i said that at the bottom of my post.. but its probably still some similar format, still with the intensity pin.. so that sucks..

Gah! Reading entire posts is for girls!

I was just thinking... isn't the real reason we don't like using these things is because CGA can only do a handful of colors? Perhaps just for black and white something could be worked out? My mind!

Aidan · « **Reply #5 on:** April 17, 2005, 09:18:37 pm »

If you're sure it's using an intensity pin, then it's not worth keeping. What drives you to think it uses an intensity pin or is a digital monitor?

As far as CGA goes, it supported two levels on each of the RGB lines, which gave a grand total of eight colours (including black/white). There was an additional intensity line, which brought the total to sixteen colours (including black/white/bright black/bright white). As the device is a TTL device, you're fixed to those colours, without a huge amount of hackery on the board...

phreak97 · « **Reply #6 on:** April 18, 2005, 02:28:44 pm »

no, i am not at all sure it is an intensity pin. the only thing i am sure of is that it is a really bigass monochrome monitor and has a db9 connector on it. the whole problem is that it doesnt match any of the db9 monitor pinouts i could find.. all of them have vital pins missing. the connector literally only has 6 pins, and the others arent broken, they were never there to begin with.
i posted the photo in the hopes someone out there might be able to tell me its pinout.
the monitor apparently came bundled with a matching video card when it was new. if you google the model number from the photo, it does have some results, but i didnt find anything that might tell me how to use the thing..

how do you get 'bright black'?

Adeptus · « **Reply #7 on:** April 18, 2005, 09:23:25 pm »

For us humans, I think it's usually called 'grey'

phreak97 · « **Reply #8 on:** April 20, 2005, 02:28:59 am »

then what about bright white as opposed to regular white?

Aidan · « **Reply #9 on:** April 20, 2005, 06:48:35 pm »

According to IBM, black is black. Bright black is light gray, white is dark gray, and bright white is bright white. No, I don't know why bright black is brighter than white.

According to some other manufacturers, black is black, bright black is black, white is gray and bright white is bright white.

Lawrence · « **Reply #10 on:** April 20, 2005, 11:40:57 pm »

Ouch, my brain.

Endymion · « **Reply #11 on:** April 21, 2005, 12:35:22 am »

According to Peter Molyneux, black and white is the greatest realtime strategy game ever made.

phreak97 · « **Reply #12 on:** April 21, 2005, 12:51:03 am »

lol i guess this means nobody knows how to work my monitor?

Aidan · « **Reply #13 on:** April 21, 2005, 11:35:54 am »

Nope, but a good start would be to try and identify the ground pins on the connector.

That way, at least you know which pins are expecting signal! You can also check the resistance of the various pins to try and identify which might be video and which might be sync.

phreak97 · « **Reply #14 on:** April 21, 2005, 04:09:39 pm »

what resistance am i looking for?

Aidan · « **Reply #15 on:** April 22, 2005, 07:33:47 pm »

Typically the video connections have a low resistance, and the sync connections have a high resistance. That may not be the case if the monitor really is TTL, but I'm not sure why anyone would make a monocrome TTL monitor!