NCR 7158, Owner'S Manual

Page: 287 / 314

Chapter 8:
Universal Serial Bus
About the Universal Serial Bus
The Universal Serial Bus (USB) is a peripheral bus for personal
computers that was first released in January 1996. Since that time,
virtually all Intel Architecture personal computers have the hardware
to support USB, and a large number of computers exist that have both
the hardware and software support required to interface with USB
peripherals.
Advantages of USB connections
USB has a number of advantages over legacy connection schemes (e.g.,
serial RS-232). These advantages include:
•
High Speed: up to 12 MB/second for high-speed devices.
•
Plug and Play: Devices are automatically recognized and
configured at installation.
•
Hot plug: Bus supports installation and removal of devices with the
power applied.
•
Up to 127 devices: One host can support up to 127 devices with the
use of hubs.
•
“Free ports”: Most PC architecture machines contain two USB ports
in the base hardware.
These advantages have become attractive to the POS industry for a
couple of reasons.