Computer Architecture Notes

Input Devices

• Graphics Table
• Cameras
• Video Capture Hardware
• Trackballs
• Barcode Reader
• Digital Camera
• Gamepad
• Joystick
• Keyboard
• Microphone
• MIDI Keyboard
• Mouse
• Scanner
• Webcam
• Touchpads
• Pen Input
• Electronic Whiteboard
• Magnetic Key Cards

Output Devices

• Monitor
• Printers
• Plotters
• Projector
• LCD Projection Panels
• Computer Output Microfilm (COM)
• Speaker(s)
• Radio

Both Input and Output

• Modems
• Networks cards
• Touchscreen
• Headsets
• Facsimile (FAX)
• Audio Cards / Sound Card
• USB

Random Access Memory

• Is volatile, meaning when the power is switched off, everything stored in the RAM is erased
• Programs (currently running) and Data (related to those programs) stored in RAM

Central Processing Unit

• Has 2 components: Control Unit and Arithmetic Logic Unit
• ALU performs arithmetic operations and evaluates logical statements
• Control Unit executes the program line by line and works as an interface between Input/Output devices, ALU, and RAM

Computer Architecture Diagram

Fundamentals of Computer Architecture

Computer responds to only two things—on and off

• 0 = off
• 1 = on
• ^ two states, on and off, so binary was chosen
• 0 = electrical pulse doesn't go in
• 1 = electrical pulse goes in

Binary

• 0 bit
• 1 bit

Every symbol on the keyboard is called a character, including spacebar and special symbols

• Combination of eight bits, called a byte, code for a character
• Every character on the keyboard is represented by a byte
• BYTE AS IN STORAGE BYTE i.e. gigabyte
• Pattern of electrical pulses is stored and becomes visual

Operating system does resource management

• Helps computer wake up and shut down and connect screen and mouse and printer, etc

Jobs are there and each job is given a priority

• Certain people are given a priority for jobs and which job gets done first depends on this priority

Compiler takes the high level language program from the user, checks in for any errors, displays them to the user to correct them, and after the errors are fixed, convert the ENTIRE program into machine language/binary language/object code/binary code/machine code.

• It converts high level language to binary to check for errors, converts it back to high level language to display to the user, takes the corrected program and converts it back to binary, gives the binary corrected program to the computer for execution, then takes the result and converts it to high level language to display to the user.

Interpreter is a systems program that takes in the high level language and converts it, statement by statement, into machine language.

• It also corrects errors along the way.
• You get output immediately

Source Code --> Compiler/Interpreter --> Object Code

Object Code: binary code/language, machine code/language, executable

Source Code: high level language (Java, C++, Python, etc)

Application Software and Systems Software

• Application Software: a software for a particular system
• System Software: use them all the time but in background (example: operating system, compiler, drivers)

When you boot your operating system, it is checking that everything is working