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CSCI 1200 / ASSC 1000. [email protected]. Software. program : instructions for hardware. makes computers useful. early computers : re-wiring. today : programming languages. Fast & Stupid. very basic instructions : math, logic, move & copy values, etc… results achieved through speed. - PowerPoint PPT Presentation
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CSCI 1200 / ASSC 1000
Software
• program : instructions for hardware.
• makes computers useful.
• early computers : re-wiring.
• today : programming languages.
Fast & Stupid
• very basic instructions :• math, logic, move & copy values, etc…
• results achieved through speed.
• computers are unforgiving, instructions must be precise.
Programming
• algorithm – general procedure
• programming – handle the specifics
• debugging – finding and fixes errors.
Languages
• Machine Language
• Assembly Language
• High Level Programming Language
• Natural Language
Machine Language
• understood by the hardware.
• executed by the CPU.
• binary strings.
• instruction set.
Assembly Language
• mnemonics mapped to bit strings.
• slow & error-prone for people.
• better hardware performance.
00000100 10000000
00000000 10000001
00000101 10000000
00001111 00000000
LOAD 128
ADD 129
STORE 128
HALT
High Level Language
• more familiar for people.
• english-like structure.
• examples : C, C++, Java, FORTRAN, and Visual Basic.
High Level Language
var x;
var y;
if (x == 2) then
x = y + 1;
else
x = 0;
print(“the value of x is ”, x);
Translation
• Compiler / Interpreter
• source code to machine code.
• high level language is hardware independent, but translated to hardware dependant machine code.
Kinds of Software
• Translation Software
• System Software :• Operating systems (Wiindows, UNIX,etc) • “talk” to the hardware
• Application Software :• use operating system and hardware to do
something, MS Word, netscape etc.
System Software
Operating System : • communication with peripherals• coordination• storing and retrieving data • running programs • managing memory• network communications• resource monitoring, account, security
System Software
Operating System Details :
• Windows XP, Mac OS X, UNIX, Linux, Window CE
• platform : OS and hardware (Wintel).
• emulation : like something else.
System Software
Utility Programs :
• repairing damaged files.
• copy files from one storage device to another.
• guarding against viruses.
• may look like are of the OS.
System Software
Device Drivers :
• control and interface a hardware component or peripheral.
• may come with the operating system, or with the component.
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..