Hardware and Software

Hardware and Software

• Chapter 2

Learning Objectives

• Identify and discuss the role of the essential hardware components of a computer system.
• List and describe popular classes of computer systems and discuss the role of each.
• Outline the role of the operating system and discuss how operating systems have evolved over time.
• Identify and briefly describe the functions of the two basic kinds of software.

Computer System Components

• Math calculations

• Access, decode, coordinate instructions

• Hold program instructions and data

Hardware Components in Action

• Instruction phase
• Step 1: Fetch instruction
• Step 2: Decode instruction
• Execution phase
• Step 3: Execute the instruction
• Step 4: Store the results

Execution of an Instruction

Processing and Memory Devices

Processing Characteristics and Functions

• Machine cycle time: Time to execute the instruction phase
• Clock speed:
• Rate at which electronic pulses are produces.
• Measured in MHz
• Wordlength
• Bit (Binary digiT): 0 or 1
• Unit for moving data
• Wordlength: The number of bits a CPU can process in a unit time
• 32-64 bit processors

Moore’s Law

• Number of transistors doubles every 18 months

Number of Bytes

Types of Memory (1)

• Random access memory (RAM)
• Volatile
• Extended Data Out (EDO) RAM
• Dynamic Ram (DRAM)
• Synchronous DRAM:
• Faster transfer speed between memory and processor

Types of Memory (2)

• Read-only memory (ROM)
• Non-volatile
• Permanent data and instructions from manufacturer
• Types
• PROM: Programmable
• EPROM: Erasable programmable