Operating System Support

• Convenience 
• Making the computer easier to use 
• Efficiency 
• Allowing better use of computer resources

Operating System Services

• Program creation 
• Program execution 
• Access to I/O devices 
• Controlled access to files 
• System access 
• Error detection and response 
• Accounting

Types of Operating System

• Interactive 
• Batch 
• Single program (Uni-programming) 
• Multi-programming (Multi-tasking)

Early Systems

• Late 1940s to mid 1950s 
• No Operating System 
• Programs interact directly with hardware 
• Two main problems: 
• Scheduling
•  Setup time

Operating System Support