USB

From Mac Guides

Acronym for: Universal Serial Bus

Apple helped to pioneer the USB standard by including it on the first iMac, the iMac G3. Since then, USB has become the industry standard for low to moderate speed data transfers and peripheral connections. With the advent of USB 2.0, data transfers are much faster and suitable for use on items like external hard disks drives, external CD/DVD burners, and recent iPods. To fully understand the difference between the terms "bits" and "bytes" used in this article, please refer to Bits And Bytes.

1 USB 1.0
2 USB 1.1
3 USB 2.0
4 Hubs
5 Notes
6 Links

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USB 1.0

USB 1.0 was never used on Macintosh computers and few devices were made to support it.

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USB 1.1

Commonly referred to as 'USB 1' (see note above)
Supporting Low-Speed (1.5Mbits/sec) and Full-Speed (12Mbit/sec) transfers.

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USB 2.0

USB 2.0 uses the same physical interface as USB 1.1 and is backward compatible with USB 1.1 devices but, includes support for Hi-Speed (480Mbit/sec) transfers on USB 2.0 devices.

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Hubs

If you should run out of available USB plugs on your computer, it is safe to 'hot-swap' (disconnect and reconnect devices without shutting down the machine) devices like printers and digital cameras. If one of the devices connected is a USB Flash Drive, or a USB Hard Drive, remember to eject the media before unplugging, otherwise you run the risk of corrupting or loosing data recently written to that device. Another possibility to consider would be purchasing a USB hub to add more ports. It is generally recommended that you purchase a 'Powered' hub, as this will ensure that all connected devices receive sufficient electricity.

The Belkin TetraHub USB 2.0 hub is an example of a deice that is able to provide the full USB 1.1 bandwidth to each port that has 1.1 devices connected to it (assuming, of course, that it is connected to a USB 2.0 computer).

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Notes

Apple was a bit sluggish to release Macintosh systems with USB 2.0 built-in. This made some people upset, especially in light of the discontinued support of the FireWire interface with the recent iPods.

All currently shipping Apple Macintoshes feature USB 2.0 ports. It is also worth remembering that the ports on Apple's USB Keyboard are USB 1.1 only. If you are in doubt you should check the manual for your computer or look up the technical specifications on Apple's website or check through the relevant MacRumors' guide pages.