I just received my new Cinema Display 20" and have it all hooked up.

However, I would like to also run the previous monitor which is a NEC Accusync LCD 17" as a second monitor. I'm told this would be particularly beneficial when using photoshop.

There is only one port on the back of the PowerMac which fits the monitor.

There is another port which has 3 rows of 10 pins which is not being used.

Is there a way I can run both monitors simutaneously?

Thank you in advance.


8 Years
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Last Post by Amy M.

Yeah, although you'll need to add another video card. Get a PCI video card (note that it's just PCI -- PCI Express, or PCI-E for short is a completely different interface), and make sure it has the correct output. If your monitor has a plug that looks like this:
Then it supports DVI and you should look for a PCI video card which supports DVI output.

If the only monitor input you have looks like this:

Your monitor only supports VGA, and you should look for a video card which supports VGA output. Note that it might also be advertised as SVGA, which is essentially the same thing.

If your monitor supports both, go with DVI as it's a purely digital signal and will therefore result in a higher picture quality.


Thank you for the great information, John. The pics were very helpful too.

The PowerMac has the DVI connection and while the NEC has a VGA, it came with the DVI adapter, so I am all set for DVI.

I'm going to try to identify what the other connector is on the back of the PowerMac. Now it has made me curious.

Thanks again.



Ok, the other connection is an ADC port. It's intention was to enable the use of 2 monitors, but was abandoned after the Power Mac series. http://upload.wikimedia.org/wikipedia/commons/thumb/0/09/AppleDisplayConnector.jpg/220px-AppleDisplayConnector.jpg

BUT there is a DVI to ADC Adapter still available.

My new question is since the monitor is VGA, but with adapter becomes DVI, is it "safe" to use 2 adapters back-to-back?

In other words, it would be Monitor (VGA) connected to DVI Adapter, which would be connected to the ADC Adapter, and then to the ADC connector in the back of computer.

Would an additional PCI graphics card still be preferable to the Adapter?


>is it "safe" to use 2 adapters back-to-back?
I doubt it. It gets a little tricky because VGA is analog, while DVI is digital, and converting the signals back and forth a couple of times likely won't work (see this).

A simpler solution would be to connect the NEC Accusync LCD 17" to your PowerMac's DVI port with your DVI to VGA adapter. Then, buy the ADC to DVI adapter and use that to connect your Cinema display to your ADC port.


Good to know.

Unfortunately, the second and most viable option costs a lot more. Lucky me.

Guess I'm back to the PCI card.



I was thinking of the other way around. The ADC monitor to DVI port were around $100.

Yes, the DVI monitor to the ADC port are much more reasonable. Thanks for pointing it out.

By going from DVI (monitor) to ADC port, is it likely to sacrifice any picture quality?


>By going from DVI (monitor) to ADC port, is it likely to sacrifice any picture quality?
Nope, because the image signals that run through the ADC are digital (as compared to the purely analog VGA). ADC essentially is DVI with a few add-ons thrown in.

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