But the limitation with previous macs is purely available power output, correct?
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MacBook Air SuperDrive Accessory Needs High-Power USB Port
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It would seem so. A standard USB port can provide half an amp of current. If a high power device expects to be able to use the majority of that, it must be connected directly to a port, or to a powered hub. The new iMac appears to be able to treat a single USB connector as multiple USB ports.
On a typical machine, that half-amp has to be split between the keyboard and the two ports it has. High power devices tend to be those that just barely slip in under that 500mA cap, and so once the keyboard takes its share, there is insufficient available power for the other device(s).
http://www.everythingusb.com/plextor_px-608cu.html
shows a USB powered DVD writer.. from 2006.
http://www.mobilemag.com/content/100/337/C12196/
shows a panasonic offering..
Wow, google is really quite useful!!
My guess is that they both use one port for data and a second port for power.
Samsung have got one too - and it's been a contender for me ever since the air was out - USB bus powered & lightscribe. Just need to find out if that bus powered rating depends on one or two USB ports... but I can't track it down on the Samsung website!
I would agree with the first part, but not with the second part. The USB port is fully compliant. A port that doesn't provide enough power wouldn't be compliant, but one that can provide more than 5V / 0.5 Ampere is fine. It works with every device that is within the USB specs.
The drive, however, is not compliant if it doesn't work with a 5V / 0.5 Ampere port. Now if Apple puts a big sticker on it "works only with MacBook Air", then I'd say it is fine. If they don't, then a customer would be right to complain.
Sounds about right with Apple. Why make a device that other could use on other various machines... even PCs and Linux machines? Good job Apple, way to make an entire ultra portable ultra light system half as useful as it could be.
Thanks Apple.
Thanks Apple.
Engadget confirms that the Macbook Air Superdrive uses a standard USB connector and the MacBook Air's USB port provides the additional juice necessary to power the drive.
Engadget also reports powered USB hubs cannot run it nor can a MacBook Pro they had handy.
So looks like it is MacBook Air only unless someone makes a hub that pushes more then .5A over the port.
Engadget also reports powered USB hubs cannot run it nor can a MacBook Pro they had handy.
So looks like it is MacBook Air only unless someone makes a hub that pushes more then .5A over the port.
Sounds about right with Apple. Why make a device that other could use on other various machines... even PCs and Linux machines? Good job Apple, way to make an entire ultra portable ultra light system half as useful as it could be.
Thanks Apple.
The problem is only with the drive, not the "entire ultra portable ultra light system."
There is no requirement whatsoever that a USB device be limited to 5V/0.5A power, even if the drive is advertised as USB-powered (this one is not). A USB device is free to use any method it pleases to meet its power needs.
It's called the "MacBook Air Superdrive"--it doesn't get any bigger than that.
One method that doesn't work is plugging it into any USB 2.0 conforming USB port. It doesn't have any methods that don't involve a USB connector. That is different from say my printer which has a USB connector and a 220 Volt power cable.
With your argument, you could call an external disk drive with a working Firewire port and a broken USB port "USB conforming", or one with a broken Firewire port and a working USB port "Firewire conforming".
The device has different resistance, which will allow for different amount of current.
It's not just the optical drive, it's the whole system, it's just like the iPhone. Most people don't just have issues with AT&T they have issues with AT&T and the iPhone as well.
The optical can't be used on any other device, so it's pretty useless unless you have a MBA. The battery can't be replaced, only 1 USB port, still kinda large for a lightweight, WiFi is the ONLY option, etc...
Not that the machine isn't a good machine, just that in typical Apple fashion you have to put up with Apple's limitations and many times crippled hardware to get that one or two features that you are looking for. I'm not trying to knock Apple, but I wouldn't mind if they stopped doing things like this to make their hardware a bit more versatile. The software is amazing, but the stuff it runs on is a bit disappointing.
No, you couldn't. If it transmits data on the USB port, it works. A broken port would not transmit and doesn't have anything to do with anything. Is your printer "nonconforming" when you don't plug it in? Of course not. The problem isn't with USB communication.
There's no requirement for power. None.
Not correct. The port can supply as much current as it is designed to supply to any device.
They are just capable of supplying more current/power than normal USB ports.
I am a consumer who would have purchased the $99 drive. There's a lost sale, Apple.
Basically my same problem. I know that I can go to LaCie adn get a portable Firewire 400 optical drive for $140. For $90 I can get the USB version. If I wanted a cheap second burner for my mobile system I could have gone with the Apple model if it was slot loading but alas, they make it compatible with only the MBA.... many lost sales Apple.
What did LaCie do that Apple couldn't do?
Where did you read that? Extra current is one thing, a peripheral only takes as much as needed, but 30V will almost certainly destroy some 12V devices.
The external drive can probably be powered by a dual usb cable, one for power and one for data. However it is almost certain that someone will release a power supply for it.
I read it somewhere, but this is close:
About the G5 Power Mac (my emphasis):
About the iMac G5:
From here: http://developer.apple.com/document...h_FireWire/Articles/FireW_implementation.html
And this about the MacBook *from the same site:
Anyway. Close enough: There's a huge difference in output on the firewire port, depending on the "giver".
I went and read up about it and you are right. However i think the output voltage is governed by the device attached rather than always being 25V. I'll get my friend with a mac pro to confirm that.
However for bus powered devices it's the current that decides whether the port can power device or not.
The provider cannot regulate the voltage. If you plug in an "non-smart" charger, which is built for 110V into a 220 outlet, it _will_ go "poof!"
However, most pro and semi-pro fw-equipment will take anything from 5-30volts. I say "Most", because I just realised I read about this when I bought my small recorder. It will take from 8 (I believe) and up to 20 volts. I seem to remember a warning about making sure the plug wasn't a 30-volt one.
Well, yes. But since theres a huge difference between, say, 1A @9V and 1A@25V, that means a alot.