Assembler Directives - EQU

EQU - links a name (label) to a value. Similar to defining a constant in C++.

Usage:
label EQU value

BACK_SP EQU $08 ASCII code for backspace

Equates BACK_SP with the hex value $08 which is the ASCII code for backspace. In programs we can now use the word BACK_SP to represent $08. This makes our program much easier to read and modify. Once an expression has been equated to a value it may in turn be used in other equate directives, example:

Length EQU 30
Width EQU 25
Area EQU Length*Width