12 Glossary
hexadecimal
A number system that uses 16 as the base. (Place value indicates
powers of 16.) It uses the digits 0-9 and A-F. Used around computers
because a byte (eight binary digits) easily converts to a two digit
hexadecimal number. Hexadecimal numbers are often indicated with
the letter H, a dollar sign, or a subscripted 16 after the number.
Compare binary, decimal.
host adapter
An expansion board that serves as a controller for SCSI devices.
hot key
Combination of two or three keys (such as Ctrl-Alt-D) that you press
simultaneously for a particular function.
hot plugging
The ability to add and remove devices to a computer while the
computer is running and have the operating system automatically
recognize the change. The Universal Serial Bus (see USB ) external
bus standard supports hot plugging. This is also a feature of
PCMCIA. Hot plugging is also called hot swapping.
I
IDE
Intelligent Drive Electronics. A hard drive type that has controller
electronics built into the drive and delivers high throughput.
interface
A connection that enables two devices to communicate.
interrupt
A signal from part of a system, such as an I/O device, asking to use
the CPU. Interrupts are hierarchical, which prevents interrupts from
interrupting each other. (Whichever interrupt has higher priority
makes the other interrupt wait.) When the CPU receives an interrupt
signal, it saves what it is doing, processes the routine associated with
the interrupt, then returns to what it was doing.