Introduction to Computers Lecture 1.1 Doug Hogan, Penn State University CMPSC 100 – Computer Fundamentals and Applications
Questions? Questions on syllabus?
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Attributes of Computers Speed Reliability Accuracy Storage Communication
Applications Word processing Financial management Shopping Entertainment Many more…
Components of a Computer Central processing unit (CPU) Memory Input devices Output devices Storage devices
Central Processing Unit (CPU) Basic job: handle processing of instructions What’s an instruction? Two parts: Control Unit (CU) Arithmetic and Logic Unit (ALU)
The ALU Built up from digital logic gates AND OR NOT most primitive level
Memory Holds programs that are currently running and the data being used by those programs. Two categories: Read-only memory (ROM) can only read data Random-access memory (RAM) can read and write information
Memory: sizes base unit: 1 bit = binary digit, 0 or 1 8 bits = 1 byte (B) 1000 bytes ≈ 1 kilobyte (KB) 1000 KB ≈ 1,000,000 B ≈ 1 megabyte (MB) 1000 MB ≈ 1,000,000,000 B ≈ 1 gigabyte (GB)
Memory Related data organized into files
Storage Devices Floppy disk 3.5 inches, 1.44 MB Hard disk typically sizes in GB Compact disc (CD) MB CD-ROM: read-only memory CD-R: recordable CD-RW: rewritable
More Storage Devices Digital Versitale/Video Disc (DVD) 4.7 GB Zip disks and tape drives varies
Input Devices mouse keyboard scanner camera microphone
Output Devices monitor cathode ray tube (CRT) liquid crystal display (LCD) printer speakers
Hardware vs. Software Hardware essentially, things you can touch input, output, storage devices Software essentially, what the computer knows data, 0s and 1s programs
Software Overview System software Controls basic operations of computer The operating system manages memory, files, application software File management tasks – deleting, etc.
Software Overview Application software Not essential to system running Enables you to perform specific tasks Ex: Office software Web browsers Media players Games
Keyboard
Keyboard Specifics CapsLock and Shift NumLock and numeric keypad Esc Editing and navigation keys insert, delete, home, end, page up, page down Function keys Ctrl, Alt PrintScreen
Mouse: operations & buttons Click – left button Click and drag Shift-click, Ctrl-click Double click Triple click Right click Scroll wheel