First there was batch Serial processing Waiting jobs sit on a job queue until they can be processed Things processed in first-in first-out order (FIFO)

Jobs.. Data, things to do Things done, output results Machine Domain Job QueueJob execution Batch processing

An IBM punch card To read a card one character at a time

Programs used punched cards

We create codes using presence or absence – hole punched 1 0 Presence Absence =I This concept has carried through to modern computing – codes used to identify characters and letters.

Input and output Machine Domain Job execution Interactive processing

Software Application System UtilityOperating System ShellKernel Software classification

Kernel Shell User

Starting the system up Bootstrap – BIOS (Basic Input Output system) Permanently written instructions that load the operating system software into the computer memory

A process Set of instructions Data (new, modified) Current state –At what point in instruction set –State of data being processes

Time sharing Time Proc A Proc B Proc A Proc B swap