1. What is computer hardware? Computer hardware are the physical components of the computer.

2. Input/Output Devices Input/Output devices provide communication between user and hardware. – Input Devices Keyboard Mouse Scanner – Output Devices Monitor Speakers Printer

3. Processors and Memory Central Processing Unit (CPU) – Performs basic functions, millions and billions of times per second (brains of the computer) Random-Access Memory – Stores data used by the CPU (before and after processing)

4. Data Storage Data storage uses a variety of media. Capacity is measured in bits and bytes: – A bit represents the on or off state of a transistor (symbolized by a 1 or a 0). – A byte is eight bits. – A kilobyte is 2 10 or 1,024 bytes. – A megabyte is 1,048,576 bytes.

5. Hard Drives The hard drive is the primary storage device in a computer. Hard drives are: – Long term, rewritable storage – Large capacity – Inexpensive – Fixed media (relatively difficult to move from one computer to another)

6. Removable Media Some storage devices are more portable: – CD/DVD Medium capacity Inexpensive Easy to transport from one computer to another – Flash, Zip, USB drives Differing capacities Differing price per MB

7. Computer Software Software can be divided into two categories: – Systems software includes operating systems, compilers, and utilities. – Application software runs on top of an operating system.

8. What is an operating system? An operating system (OS) manages the hardware and software on a computer system. An OS: – Manages memory and hardware resources – Allocates resources to applications – Provides a consistent interface for applications

9. Operating Systems UNIX/Linux – Multiuser OS – Multitasking – Runs on many types of hardware – Modular tools Mac OS – First mainstream graphical user interface – Icons (pictures) and mouse replaced command line interface DOS/Windows – DOS gained popularity with first PCs – Windows provided graphical interface to DOS – Windows later separated itself from DOS underpinnings

10. Low-Level Languages Low-level programming languages use simple commands to communicate with the CPU: – Machine language (most basic language of the CPU) – Assembly language (human readable, but close to machine language)

11. High-Level Languages High-level languages can be procedural or object-oriented: – Procedural languages use a step-by-step process to solve a problem. Basic, Pascal, C – Object-oriented languages model problems using objects that correspond to real-world counterparts. Smalltalk, C++, Java