1 INTRODUCTION • What is an operating system? • Early Systems • Simple Batch Systems • Multiprogramming Batched Systems • Time-Sharing Systems • Personal-Computer Systems • Parallel Systems • Distributed Systems • Real-Time Systems What is an Operating system A program that acts as an intermediary between a user of a computer and the computer hardware. A systems program which controls all the computer's resources and provides a base upon which application programs can be written. Operating system goals: • Execute user programs and make solving user problems easier. • Make the computer system convenient to use. • Use the computer hardware in an efficient manner. Computer System Components 1. Hardware - provides basic computing resources (CPU, memory, I/O devices). 2. Operating system - controls and coordinates the use of the hardware among the various application programs for the various users. 3. Applications programs - define the ways in which the system resources are used to solve the computing problems of the users (compilers, database systems, video games, business pro grams). 4. Users (people, machines, other computers).
2 Operating System Functions • Resource allocator - manages and allocates resources. • Control program - controls the execution of user programs and operation of I/O devices. • Kernel - the one program running at all times (all else being application programs). Early Systems - bare machine (early 1950s) - First Generation. • Structure o Large machines run from console o Single user system o Programmer/User as operator o Paper tape or punched cards • Early Software o Assemblers o Loaders o Linkers o Libraries of common subroutines o Compilers o Device drivers
- Spring '17
- Simple Batch Systems