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Has anybody gotten a Mini Display Port to Dual DVI cable yet?

So its 70 dollars more to use the hub? No thanks. i think there's more behind the USB plug than just to enable the USB hub in monitor. Even if what you say is true, I'd rather spend 20 or even less on a 4 port usb hub.

seeing that I dont have to spend 100 bucks to plug my computer into the current displays necessitating DL DVI, I'm content.

that said, i totally encouraged my parents to take advantage of a deal my school had. 2.5 GHz Penryn MBP for 1200 + tax. you can have your -1 FW and mini display port.
 
Display Port Dongles

Hello all,

for those interested, I found an interesting article about connecting "legacy" DVI (and HDMI) devices to the Display Port.

http://www.edn.com/index.asp?layout=article&articleid=CA6574650

Short summary:

Every adapter cable ("dongle") will need active circuitry (a "bridging circuit"), even the DisplayPort to DVI and the DisplayPort to VGA adaptors.

The native DisplayPort supports up to four differential links (each corresponding to a PCIe lane). Each of these links transports both data and a clock by means of a single differential pair.

When the DisplayPort connects to DVI, these lines will be used in an entirely different way. DVI uses one dedicated clock pair and three pairs for the colors red, green, and blue. The graphics controller detects the dongle and "misuses" the Display port pins accordingly. Then, the bridging circuit inside the dongle converts the signals to DVI compatible levels (due to constraints of the 45 nm process, this level conversion cannot be accompished by the graphics chip itself).

Now, dual-link DVI needs TWO differential pairs for each color. In this case, the "dongle" must split the high-speed differential pair for each color into two corresponding lower-speed, DVI-compatible pairs. This is why this dongle is more expensive.

I do not think that the USB is necessary for operating the display. I think Apple merely provides the USB connection for convenienve. If you connect your mouse and keyboard to the ACD, you just need to plug in the two plugs in your Macbook, and you are all set.

Hope I did not confuse everybody :)

Matthias.
 
So are you guys saying that if I had bought one of the unibody MBPs last week instead of the early 2008 model, I wouldn't be able to use it with my 30" display until a month from now when this dongle is available??? If that is the case, I am really, really glad I went with the older model.
 
convergent said:
So are you guys saying that if I had bought one of the unibody MBPs last week instead of the early 2008 model, I wouldn't be able to use it with my 30" display until a month from now when this dongle is available??? If that is the case, I am really, really glad I went with the older model.
Click to expand...

huh-huh h-huh. You said Dongle.

Shut up Beavis.

end/ childish behavior.

Yes, they are. Just like you would not have been able to get the new 24" Cinema with a new MacBook or Pro until recently as they were not available when announced with the new notebooks. Such is life with Apple, often things are introduced but delayed in availability while others are in the supply chain and in stores that day or the next.
 
Nautigar said:
Hello all,

for those interested, I found an interesting article about connecting "legacy" DVI (and HDMI) devices to the Display Port.

http://www.edn.com/index.asp?layout=article&articleid=CA6574650

Short summary:

Every adapter cable ("dongle") will need active circuitry (a "bridging circuit"), even the DisplayPort to DVI and the DisplayPort to VGA adaptors.

The native DisplayPort supports up to four differential links (each corresponding to a PCIe lane). Each of these links transports both data and a clock by means of a single differential pair.

When the DisplayPort connects to DVI, these lines will be used in an entirely different way. DVI uses one dedicated clock pair and three pairs for the colors red, green, and blue. The graphics controller detects the dongle and "misuses" the Display port pins accordingly. Then, the bridging circuit inside the dongle converts the signals to DVI compatible levels (due to constraints of the 45 nm process, this level conversion cannot be accompished by the graphics chip itself).

Now, dual-link DVI needs TWO differential pairs for each color. In this case, the "dongle" must split the high-speed differential pair for each color into two corresponding lower-speed, DVI-compatible pairs. This is why this dongle is more expensive.

I do not think that the USB is necessary for operating the display. I think Apple merely provides the USB connection for convenienve. If you connect your mouse and keyboard to the ACD, you just need to plug in the two plugs in your Macbook, and you are all set.

Hope I did not confuse everybody :)

Matthias.
Click to expand...

you're making the assumption that the mini-Displayport is adequately powered. the info you're referring to is describing the full-size display port which may very well be powered. The USB may be used for the "bridging circuit". In a month we will know for sure. From what i've read elsewhere, on the other end of the USB/DVI dongle its just a female DVI port. IIRC, the USB data is not transferred via DVI.

take the older macbook's mini-DVI for example. It's not dual link.

now what you should be wondering is why there is no mini to full size display port adapter.
 
e12a said:
you're making the assumption that the mini-Displayport is adequately powered. the info you're referring to is describing the full-size display port which may very well be powered. The USB may be used for the "bridging circuit". In a month we will know for sure. From what i've read elsewhere, on the other end of the USB/DVI dongle its just a female DVI port. IIRC, the USB data is not transferred via DVI.

take the older macbook's mini-DVI for example. It's not dual link.

now what you should be wondering is why there is no mini to full size display port adapter.
Click to expand...

Exactly. Anyone that is claiming that the dongle somehow sends the USB signal over the DVI cable needs to think about what happens at the monitor end when it interprets the DVI signal. DVI is a standard that uses all of the pins for video --- not for USB. Although no one but Apple knows for sure, it sure looks like the USB connection on the dongle is there to help convert from displayport to dual-link DVI.

And, "exactly!" also to the "why is there no mini-to-full-size displayport?" comment. Seriously, if there is active "bridging circuitry" to go from displayport to DVI, why not simply give us a passive connection from mini-displayport to standard displayport?
 
OKay!

i have a definitive answer. Just chatted with melissa B. from apple chat.

She says the USB IS used to power the adapter. so no more bickering.

toldyaso1.jpg


toldyaso3.jpg


toldyaso2.jpg


sorry for the multiple screens grabs. I cant expand the text window larger than it is for some reason. Some of you guys apple too much credit.
 
roland.g said:
huh-huh h-huh. You said Dongle.

Shut up Beavis.

end/ childish behavior.

Yes, they are. Just like you would not have been able to get the new 24" Cinema with a new MacBook or Pro until recently as they were not available when announced with the new notebooks. Such is life with Apple, often things are introduced but delayed in availability while others are in the supply chain and in stores that day or the next.
Click to expand...


I would be pretty ticked if I bought a nearly $3K laptop and couldn't use it with my display because they don't have this adapter... which they created the need for by going with a non-standard connection. It never occurred to me that this thing wasn't available yet. I would have been lost without my 30"er. I hope this gets worked out quickly as you wouldn't think it would be that hard to make these adapters. Is there at least some added function that will be added with the new method?
 
e12a said:
OKay!

i have a definitive answer. Just chatted with melissa B. from apple chat.

She says the USB IS used to power the adapter. so no more bickering.
Click to expand...

Thanks for that info. It's only a pity that Apple does not loop the USB data signals through. So we'll lose one USB port. As mentioned above, that will be a big issue for MBA users ... :-(
 
Being prepared for shipment!

In case anybody's interested, my beautiful $99 piece of cable is now finally being prepared for shipment...
 
e12a said:
She says the USB IS used to power the adapter. so no more bickering.
Click to expand...

There IS a pass-through USB port on the adapter but it cannot be used to connect any devices that require even a little bit of power. I tried my Wacom tablet and iPod Nano with no luck. I also tried it with the laptop plugged into AC power, but that didn't help. I think the USB port may work with some sort of device that is plugged into AC power, but probably not a hard drive. The port is pretty much useless....
 

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I added some pics in my previous post. Haven't tried my 30" ACD (it's at my other place), but it works pretty good on my 24" DreamColor. Shame about losing a USB port though.

What I'd really like is to use my DreamColor with the DisplayPort so I can take advantage of the full 10-bits.
 
RAS admin said:
I added some pics in my previous post. Haven't tried my 30" ACD (it's at my other place), but it works pretty good on my 24" DreamColor. Shame about losing a USB port though.

What I'd really like is to use my DreamColor with the DisplayPort so I can take advantage of the full 10-bits.
Click to expand...

I don't fully understand the USB problem yet. I have one of the new 24 inch LED screens at work. It has a USB cable in addition to the display port and magsafe. The USB port is used to drive the three USB ports on the back of the 24 inch LED screen. Are you saying that the USB port for the MDP->Dual link DVI is exclusively used to power the adapter, but can't power USB ports on the external screen? If so, I wonder how they will deal with this when Apple comes out with new 30 inch monitors, i.e. will one have to use BOTH USB ports on the Macbook Pro to make the USB ports on the external drive accessible?

So far all I can say it the transition to MDP seems a real disaster. Poor judgment, Apple!
 
I don't know what the USB port is for. It just didn't work with the devices I tried that require power from the USB port. Maybe it works with the USB port on the new displays from Apple.

I will try a few more things in a bit:

USB scanner
USB port on RED-RAID that is plugged into AC
 
RAS admin said:
I don't know what the USB port is for. It just didn't work with the devices I tried that require power from the USB port. Maybe it works with the USB port on the new displays from Apple.

I will try a few more things in a bit:

USB scanner
USB port on RED-RAID that is plugged into AC
Click to expand...

It would be really bad if it didn't drive USB ports on the monitor. One reason it would be bad for Apple is that they promised the new Air would be able to drive a 30 inch screen, but how is this of any use if one is loosing all the USB ports?
 
Well, my USB scanner works plugged into the port on the adapter. The ports on the 30" ACD will probably work too since the monitor needs to be plugged into AC as well. I guess anything that has it's own power supply should work.
 
RAS admin said:
Well, my USB scanner works plugged into the port on the adapter. The ports on the 30" ACD will probably work too since the monitor needs to be plugged into AC as well. I guess anything that has it's own power supply should work.
Click to expand...

Ah, that makes sense! Looking forward to hearing what you find, and trying this out myself hopefully soon...
 
Couldn't you buy a cheap iPod Charger and plug the USB cable from the Dual-Link DVI adapter into that?

Save you using a USB port on your Mac, and you can easily buy a 1.5M USB extension cable for $10 if the USB cable isn't long enough to reach a power socket.

images
images
 
Kilamite said:
Couldn't you buy a cheap iPod Charger and plug the USB cable from the Dual-Link DVI adapter into that?

Save you using a USB port on your Mac, and you can easily buy a 1.5M USB extension cable for $10 if the USB cable isn't long enough to reach a power socket.

images
images
Click to expand...

After reading through this thread for the first time, I was *just* about to post that! ... I think you're on to something. I wouldn't see why that wouldn't work. Sure, it's not a perfect solution. It's definitely an oversight on Apple's part for MBA users.
 
Kilamite said:
Couldn't you buy a cheap iPod Charger and plug the USB cable from the Dual-Link DVI adapter into that?

Save you using a USB port on your Mac, and you can easily buy a 1.5M USB extension cable for $10 if the USB cable isn't long enough to reach a power socket.

images
images
Click to expand...

how would you plug a male usb cable to a male usb cable.........thats GAY!!!!
you would need a male to female usb extension cable
 
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