What is USB
USB was developed in the 1990s in an effort to simplify connections between computers and peripheral devices. USB is short for “Universal Serial Bus” which stands for “universal serial bus” with the goal of creating a computer interface that works universally. It features cross-platform compatibility for Macintosh, Linux/UNIX, and all versions of Windows since 98SE. USB connection ports are the standard available on virtually all computing machines manufactured in recent years.
USB is the first cross-platform “hot-swappable” interface compatible with any operating system, meaning you don’t have to reboot your computer before plugging or unplugging a device. Most computers on the market include multiple USB ports, which is the interface of choice for most home and office peripherals such as printers, cameras, modems, and portable storage devices.
One of the downsides is a streamlined effect due to their Plug-N-Play nature, devices such as keyboards and mice require constant interface with the computer, thus needing to have their own dedicated USB port. They can usually be optimized together, much like Macintosh mice that can be plugged in through keyboards, but they cause issues on hubs and other “shared” devices
Something similar happens if a scanner and printer are connected to the same USB hub. If the machine is sending a print job and the scanner is used, the printer will have to stop and wait for the scanner to finish before it can continue printing. This is a huge weakness compared to FireWire, which can connect a chain of devices, even without hubs. The easiest and cheapest solution to this problem is to add ports with additional PCI or PCMCIA cards.
USB has a maximum length of 4.6 meters (15 feet). A practical solution to the distance limitation is to use extension cables that have a repeater to fill in the gaps. These cables have a small reinforcement at the end (booster), which reads and re-sends the signal instead of passing it along, with this it is possible to achieve a maximum extension of 24 meters (80 feet).
USB Types
There are currently several forms:
- USB 1.0
- USB 1.1
- USB 2.0
- USB 3.0
- USB 3.1
USB 1.0 (original) was relatively slow, about 1.5 Mbps, version 1.1 reached 12 Mbps.
USB 2.0 is by far the most common interface, with speeds of up to 480 Mbps, beating Apple’s FireWire interface which has a speed of 400 Mbps.
USB 3.0 also known as SuperSpeed USB (high speed), is the next evolutionary phase of the Universal Serial Bus with a speed of 5.0Gbps (5,120Mbps).
USB 3.1 (Type-C) has data transfer speeds of up to 10 Gbps. That’s double 5Gbps (3.0), and much more than 480Mbps (2.0). It’s even fast enough to feed video and audio to an HD display.
