Hardware Reference
In-Depth Information
USB was initially developed by Intel engineers in the early 1990s, after which the design
was transferred to the USB Implementers Forum (USB-IF) to further develop, support,
andpromoteUSBarchitecture.TheUSB-IFinitiallyconsistedofIntelplussixothercom-
panies including Compaq, Digital, IBM, Microsoft, NEC, and Northern Telecom.
The USB-IF has formally released USB versions as follows:
• USB 1.0 - January 1996
• USB 1.1 - September 1998
• USB 2.0 - April 2000
• USB 3.0 - November 2008
The 1.1 revision was mostly a clarification of some issues related to hubs and other areas
of the specification. Most devices and hubs should be 1.1 compliant, even if they were
manufactured before the release of the 1.1 specification. A bigger change came with the
introduction of USB 2.0, which was 40 times faster than the original USB yet fully back-
ward compatible. USB ports can be retrofitted to older computers that lack built-in USB
connectors through the use of either an add-on PCI card (for desktop computers) or a PC
Card on CardBus-compatible laptop computers.
Intel motherboard chipsets starting with the PIIX3 South Bridge chipset component (in-
troduced in February 1996) have included USB support as standard. In September 1996,
Toshiba introduced the first USB peripheral, a device it called the “In-Touch Module,”
which was a patented remote-control unit that included buttons for playing media along
with a volume control knob.
After Intel introduced chipsets with USB support, other chipset vendors quickly followed
suit, making USB as ubiquitous a feature of today's PCs as serial and parallel ports once
were. Although most desktop systems started incorporating USB back in mid-1996, most
laptops did not begin including USB 1.1 ports until 1998. It wasn't until then that In-
tel released a mobile South Bridge chipset with USB support. By mid-2002, virtually all
desktop motherboards included 4-6 (or more) USB 2.0 ports as standard. Laptop com-
puters were a little slower to catch on to the USB 2.0 bandwagon; it wasn't until early
2003 that most laptop computers included USB 2.0 ports as standard.
Systems with USB 3.0 ports were first released in 2010; however, these used third-party
add-on chips because Intel and AMD do not plan to incorporate USB 3.0 support in
