Glossary of Terms
Shortening a phrase by taking the first letter of each word.
ALU -- Arithmetic Logic Unit --
A circuit which adds, subtracts, compares, and does other simple but rapid
processing on small units of data.
application program --
which does something, such as run a payroll or compute the airflow
over an airplane wing.
architecture, computer architecture --
The hardware design of a computer; the layout of its internals at the
lowest level as seen by a programmer.
ASIC -- Application Specific Integrated Circuit --
Customized electronics on one chip, like buying a tailored suit versus
one off the rack.
assembler -- See:
assembly language --
Practically the same thing as
but in a form humans find (slightly) easier to read.
Basic Input/Output System - low level programs controlling computer
bit -- BInary digiT --
Can be represented by a switch being either ON or OFF; the smallest unit
stored in a computer memory.
Sending data over one wire one bit at a time, rather than in
parallel over a "bus" of several wires at once.
Any number of parallel wires carrying bits lined up like racehorses
coming out of a starting gate.
A "word" of 8 bits.
These are enough bits to encode the alphabet:
upper/lower case letters, numbers, & punctuation, with room left over.
A programming language (such as BASIC or COBOL) with a very short name.
A piece of silicon as small or smaller than a fingernail. See:
CISC -- Complex Instruction Set Computer --
The microprocessors in common personal computers have a
consisting of hundreds of individual instructions. See:
CMOS -- Complementary Metal Oxide Semiconductor --
A fabrication process for
which yields circuits that use very little power.
Lines from a computer
"object" code refers to a program which has
been translated from some different "source" code.
Translates the more English-like statements of a higher level language
like C or FORTRAN into
the computer can run.
control store --
A memory, either RAM or ROM, which contains
controller, microcontroller --
A type of microprocessor used to control appliances or monitor and control
CORDIC -- COordinate Rotation DIgital Computer --
A kind of hardware circuit which can do higher math very quickly.
CPU -- Central Processing Unit --
The heart of a computer, that element which runs programs and processes
debugger, symbolic debugger --
A software package which helps a programmer fix broken programs.
development system --
A computer system which makes it easy to write software, either for that
same system, or for a different computer type.
digital circuitry --
Is based on fast and tiny switches, interconnected to perform counting and
fiber optics --
Connection medium different from wires in which data are sent as pulses
of light rather than as pulses of electricity.
GaAs -- gallium arsenide --
compound on which can be made faster circuits than can
be fabricated on
Parts of a computer which can be physically seen or touched.
I/O -- Input/Output --
The communication sections of a computing system.
IC -- Integrated Circuit --
a device which contains dozens to millions of
transistors and other circuit
elements on a single
Sometimes also called "operation" - A single word of machine code which
performs some specific action within a
ISDN -- Integrated Services Digital Network --
One of dozens of interfaces for sending data,
basically all of which are faster than the phone lines.
A new programming language becoming popular on the Internet. See:
kilo -- K --
Prefix which means multiply by 1,000. E.g., "Kilobits per Second,"
or "KBS" - standing for a transmission rate over a wire or phone line.
language, programming language --
Software is written in programming languages with names such as BASIC,
COBOL, C, and Java. See also:
laser diode --
device which transforms an electrical signal into a coherent beam of light.
Another name for the control and computation circuitry on a chip.
machine language --
Set of all the different instructions a given computer's logic can perform.
These are very low level operations; most programmers don't work with
machine code. See:
mega -- M --
Prefix which means multiply by 1,000,000. E.g., "Megabyte," or "MB" -
meaning millions of bytes.
memory, computer memory --
can be stored, typically by the mllions. See:
Some computers have this extra level of programming which is even a step
closer to the underlying hardware than
A computer on a single chip; The
CPU found in personal computers and
engineering workstations. See also:
MIMD -- Multiple Instruction Multiple Data --
A type of parallel computer in which each unit can run its own independent
program. See also:
A software package which helps a programmer watch and modify programs as
they run. Not to be confused with the "monitor" that it is displayed on.
neural net --
A new and different type of computing circuit made from elements which
act more like nerve cells than like simple switches.
OOP -- Object Oriented Programming --
Writing software in reusable modules, as opposed to disorganized
Java is a new, popular OOP language.
OS -- operating system --
The set of programs which allow a user to tell a computer what to do,
such as DOS, Windows, or UNIX.
parallel processing --
Having many (possibly different)
CPUs running at the same time to finish programs
much faster than a single CPU possibly could.
program, computer program --
A "work order," written in a computer language, which tells a computer
how to do something.
PROM -- Programmable Read Only Memory --
Write only once, read many times.
Research / Research & Development.
RAM -- Random Access Memory --
The most common kind of computer memory; can be read or written in any
Hardware which holds a certain number of
at a time.
Registers are a small but very fast part of computer memory.
RISC -- Reduced Instruction Set Computer --
Fewer is often faster when it comes to running
ROM -- Read Only Memory --
Hard-wired memory which can't be written into.
Starting material on which computer circuits are fabricated. Neither an
electrical conductor nor an insulator.
A semiconducting element upon which most computer circuits today are
SIMD -- Single Instruction Multiple Data --
A type of parallel computer in which each unit can only run instructions
sent by a master unit. See also:
A program which runs on one computer but which acts like another, different
SOC -- System-On-Chip --
Very very large scale integration (See
the latest frontier in miniaturization of logic circuits
they run on the hardware.
Electronics based on
rather than vacuum tubes.
symbolic assembler --
A program which reads an English-like programming language and converts it
machine language. See also:
The basic electronic solid-state switch.
VLSI -- Very Large Scale Integration --
Pushing the technology so that very tiny transistors can be fabricated
so that very large numbers of them (millions) can fit on one integrated
circuit die, or "chip."
word, computer word --
A grouping of a certain number of
size is usually standardized
within a particular architecture. See: