Subroutines

Abstract

Subroutines in assembly-code (or machine-code) programming are related to procedures in Pascal: a subroutine is a series of instructions which can be called from anywhere in a program; the exact effect of the subroutine’s instructions can be varied from call to call using parameters. Just as a Pascal program may be smaller if it uses procedures because only one copy of a commonly occurring series of statements need be held in the program, so an assembly-code program may be smaller if subroutines are used. Just as a large Pascal program can be structured using procedures, so an assembly-code program can be structured using subroutines.