01:198:170 Chapter Notes - Chapter 9, 10: Operating System, Facebook Home, Clairvoyance
16 May 2018
School
Department
Course
Professor
Computer Operations
Principles of Computer Operations (Cast of Characters)
●Processor: does the work; follows the program's instructions
○Device that does the actual computing
○Equivalent terms: computer, microprocessor, central processor, CPU (central processing
unit), and core
●Operating system
○Program that performs common operations, and makes ur computer a useful device
■Adds subtracts, moves data here to there
■Loads programs, shares memories w multiple apps, locating files, etc
●Software: programs aka apps
●Instructions: tells the processor what to do
●Fetch/ execute cycle: executes the instructions
○Implemented in hardware, consists of getting the next instruction, figuring out what to
do, gathering data to do it, doing it, saving results, then repeating
●Memory: stores the data
○Stores both the program while it is running and the data on which the program operates
○Bits are a universal medium for info, and they're commonly referred to as 0 and 1
○Its the memory that stores the billions of 0s and 1s
○Both program and data are encoded as bits
●Hardware: the physical parts of the computer
Software Layers/ Software Stack
●The layers are only a conceptual grouping of software that performs similar tasks
●Bc a given layer is built with code from the level below, they are organized from more primitive
(lower levels) to more general and sophisticated (upper levels)
CPU: Control Unit
●Hardware implementation of the fetch/execute cycle
●Its circuitry fetches an instruction from memory and performs the other
●operations of the cycle on it
CPU: ALU
●Does the math
●The part of the computer that actually does the computation during
●Instruction Execute
Input Unit and Output Unit
●Inverses of each other, are the wires and circuits through which information moves into and out
of a processor
●Without input and output (that is memory, control , ALU in sealed box) is basically useless
Program Counter (PC)
●Every instruction has an address, which is the address of the memory location of the first byte of
the instruction
●Computers keep track of which instruction to execute next by its address
9
01:198:170 Full Course Notes
Verified Note
9 documents
Document Summary
Processor: does the work; follows the program"s instructions. Equivalent terms: computer, microprocessor, central processor, cpu (central processing unit), and core. Program that performs common operations, and makes ur computer a useful device. Adds subtracts, moves data here to there. Loads programs, shares memories w multiple apps, locating files, etc. Instructions: tells the processor what to do. Implemented in hardware, consists of getting the next instruction, figuring out what to do, gathering data to do it, doing it, saving results, then repeating. Stores both the program while it is running and the data on which the program operates. Bits are a universal medium for info, and they"re commonly referred to as 0 and 1. Its the memory that stores the billions of 0s and 1s. Both program and data are encoded as bits. Hardware: the physical parts of the computer. The layers are only a conceptual grouping of software that performs similar tasks.
