Instruction Set - AMSTRAD CPC464 User Manual

Instruction
A request/command to a computer to perform a particular operation. A. collection or sequence
of instructions form a program.

Instruction set

The prime logical and mathematical processes carried out by the microprocessor. Every high
level instruction (including assembler mnemonics) have to be capable of being distilled down
to an instruction that is recognised by the computer CPU. A single high level command may
invoke a large number of elements from the CPU's instruction set.
Integer number
A number with no fractional part. ie. a number with no part to the right of the decimal point -
as opposed to a real number which is the integer part plus the fractional part.
Integrated circuit
A collection of electronic circuit components miniaturised and built onto a single piece of
silicon. See also'Chip'.
Intelligent terminal
A terminal where as well as handling the requirements of the computer's input and output,
local processing power is also available when the terminal is'off line'.
Interactive
Usually a reference to programs where the hardware computer prompts the user to provide
various types of input - ranging from controlling the spaceship in an arcade game, to
answering questions in educational programs. The action of the user has an effect inreal time
on the behaviour of the program.
Interface
The way in and out of a computer, both in electrical and human terms. The CPC464 interface
is the keyboard (input), and the screen (output) - as well as the facility at the rear for the
connection of user peripherals to the interface bus.
Interpreter
A further extension of the analogy of computer instruction sets and language. The element of
the system software that interprets the high level language to the level that can be
understood by the CPU. eg. It converts BASIC code as enetered via the keyboard into the
computers own internal language..
I/O
Input/Output.
Iteration
One of the elements of computing. The computer performs all tasks by breaking them down
into the simple tasks that can be handled by the CPU. To do this, the computer must go to
and from between many simple elements until a given condition is fulfilled.