Hardware and Software

Hardware and Software

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