USB 1.1: FAQ (1 of 4)
Question 1: What is USB 1.1?
Answer: Universal Serial Bus (or USB for short) is an industry standard for connecting peripheral devices to personal computers. Apple is adopting USB in its products for a variety of reasons:
- it's an industry standard, so there will be a wide variety of solutions available to Apple customers
- it offers the true plug-and-play simplicity our customers expect from Apple products
- it's fast, offering data transfer rates of up to 12Mbps
- it can support up to 127 devices!
- it features hot plug and hot unplug--that is, you don't have to shut down iMac to connect a new or disconnect an existing USB device
Question 2: How Fast is USB 1.1 Compared to Other Connection Methods?
Answer: USB offers data transfer rates of up to 12Mbps. This compares very favorably to other Apple connection methods:
|ADB||.01Mbps||Input devices like mice, keyboards, joysticks, etc.|
|Serial||.023Mbps--2Mbps||QuickDraw printers and telephony devices|
|USB||12Mbps||All of the above, and more|
|Ethernet||10/100/1000Mbps||Laser printers, network connections, etc.|
Answer: A hub is a USB device that includes extra ports into which other USB device can be attached. Some hubs, like the keyboard, are bus powered, deriving their power from a source on the bus to which they are attached.
Others are self-powered. These come with an AC adapter that plugs into an electrical outlet and supplies power to the hub. There are several companies that sell hubs today.
Some self-powered hubs are likely to function solely as hubs, acting as a source of power and allowing you to plug several downstream devices into them. Other devices may include a built-in hub (like the Apple USB Keyboard) that serve a primary function but also provide other ports into which another device can be connected.
Other USB FAQ's can be found in the following articles:
- Article 30651: "USB 1.1 FAQ (2 of 4)"
- Article 30652: "USB 1.1 FAQ (3 of 4)"
- Article 30653: "USB 1.1 FAQ (4 of 4)"