Understanding Computers: Fundamentals of Bit Strings, Memory, and Input/Output Devices
Dive into the essentials of computer science with this comprehensive overview, focusing on bit strings, how we represent data through ASCII and Unicode, and understand the crucial concepts of volume and storage capacity (KB, MB, GB, TB, PB). Explore the anatomy of the CPU, its parts, and how it processes instructions. Gain insights into different input and output devices, from keyboards and mice to printers and monitors, and learn about the importance of memory types such as RAM, ROM, and secondary storage. Ensure you are well-equipped with the knowledge of computing fundamentals.
Understanding Computers: Fundamentals of Bit Strings, Memory, and Input/Output Devices
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Presentation Transcript
CSCI 1200 Introduction to Computing Julie Benoit jbenoit@cs.dal.ca
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
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! 2@ 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
