CSCI 1200 Julie Benoit Introduction to Computing

Bit Strings Represent numbers. alphanumeric : ASCII / Unicode. instructions. other stuff : sound or image data for example.

Volume / Size / Capacity Kilobyte (K) – thousand bytes Megabyte (MB)– million bytes Gigabyte (GB) – billion bytes. Terabyte (TB) – trillion bytes. Petabye (PB) – quadrillion bytes. Note : MB vs Mb

Volume / Size / Capacity 1 K : text on back of DVD case. 1 MB : 1.5 sec of DVD quality video. 1 GB : a little less than 30 minutes of DVD quality video. 1 TB : about 230 DVD movies. 1 PB : about 238,600 DVD movies.

CPU Central Processing Unit. converts input to output. carries out instructions. mathematical & logical operations. communicates with other devices.

CPU motherboard : – circuit board. –location of the CPU. Compatibility : –instruction sets Performance / Speed : –clock speed, GHz.

CPU Parts ALU – arithmetic logic unit. Bus – data travels in parallel. Cache & Registers – high speed, local memory.

Computer Speed Instruction set Word Size Access Speeds Specialized hardware Parallel processing Clustering multiple machines Memory

main memory / RAM. CPU reads main memory. addressed cells (Random Access). info held using electrical current: –need for ROM, CMOS, Flash & secondary memory.

Memory ROM : read only memory, non-volatile. CMOS : low energy, battery powered RAM, date & time. Flash : fast, only needs power to change, portable devices. Secondary memory : long term storage.

Memory main memory / RAM. CPU reads main memory. addressed cells (Random Access). info held using electrical current: –need for ROM, CMOS, Flash & secondary memory.

Storage magnetic tapes magnetic disks (floppy disks) hard disks optical disks (CD, DVD, Blu Ray) solid state devices (memory sticks & cards, USB flash drives)

Input Devices Keyboards : Qwerty / Dvorak / Alphabetic ergonomic compact membrane one handed folding

Input Devices `~ 1! 3# 4% 5^ 6^ 7& 8* 9( 0) [\{ ]} \\| '", p y f g c r l /? += a o e u i d h t n s -_ ;: q j k x b m w v z

Input Devices Pointing Device : selecting from options / menus. spatial tasks / graphics applications. efficiency

Input Devices : Pointing Mouse : mechanical, light Touch Pad : finger pressure Track Ball : upside down mouse Pointing Stick : TrackPoint, Isopoint Joystick : and other gaming devices Tablet & Stylus Touch Screen

Input Devices : Reading Optical Mark Readers Bar Code Readers Magnetic Ink Character Readers RFID Tags & Readers

Input Devices : Reading Optical Character Recognition Handwriting recognition Smart Whiteboard

Input Devices : Digitizing Scanner Digital Camera Video Digitizer Digital Video Camera

Output : Monitor most familiar (VDT) diagonally in inches pixels, dpi, resolution colour depth : number of colours that can be displayed at one time video adaptor / video card VRAM

Output : Monitor Liquid Crystal Display Cathode Ray Tube

Output : Printers impact & non-impact dot matrix printers & line printers laser & ink jet resolution plotter multi-function devices.

Colours light & pigment are different Pigment : cyan, magenta, yellow & black Light : red, green, blue

Sound Output sound card – accept a microphone, play sound through speakers & headphones. all Macs & some PCs have on board sound. synthesized speech, music, & sounds.

Fax Machines / Fax Modems phone lines dots to create the image

Combined Devices some devices do both I/O. peripherals interface with the world.

Ports, Slots, Buses & Bays port : connect a device. Slot : place to insert a special piece of hardware. Bus : group of wires connecting bays, ports and slots to the CPU. Bay : open space in the box for a storage device.

Standard Ports serial port : one bit at a time, modem parallel Port : groups of bits, printer keyboard / mouse ports USB ports faster, generic, multiple devices, various standards

Special Ports on expansion cards video port for the monitor microphone, speaker, MIDI for attaching sound equipment network card adds a port to connect to the LAN