Computer Science

mouse, keyboard, graphics card, hard disk drive

Examples of computer hardware

Herman Hollerith

He invented the "Tabulating Machine."

Hard Drive

PERMANENT; holds programs and data (8TB)

RAM (Memory)

TEMP.; data is erased when the computer is shut down (megabytes)

Bus (Key components inside the computer)

connects all the different parts of the computer together

Alan Turing

created an electromechanical machine to break German Ciphers

Second Generation Computers

used transistors instead of vacuum tubes; relied on punch cards for input and printers for output

Solid State Drive

A replacement for hard disk drives; have no moving parts = less prone to failure

Utility Programs

A small program that performs many of the general housekeeping tasks for the computer (ex. file explorer)

Integrated Circuit

A thin slice of silicon that contains many solid-state components.

System Clock

Acts a metronome; each tick executes the next instruction (clock speed is measured in Hertz)

Seek Time (Disk Scheduling)

Amount of time it takes for the heads to reach the appropriate cylinder

IBM 360

An early third-generation computer that is widely regarded as the first general purpose mainframe

Cache

Data is more accessible than the RAM; only a small amount of data can be stored here and NOW

Output

Displays data in a human readable form

Punch Cards

Early computers used these as input commands

Fifth Generation Computer

Enhancement of Artificial Intelligence (Present)

ENIAC

First electronic general-purpose computer (University of Pennsylvania)

Altair 8080

First personal computer; "make it yourself"

Input

Gathers data often from user entry

IBM 400

General purpose system; used punch cards for input and line printer for output

Found the first computer bug on the Harvard Mark 2

Grace Hopper

Charles Babbage

He is known as the "Father of Computers." He developed the Difference Engine and the Analytical Engine.

Motherboard (Key components inside the computer)

Holds the CPU, Memory, system Bus; main circuit board

Scan Disk (Disk scheduling techniques)

In this algorithm the head acts like an elevator; moving towards the center, then away

Hard Disk

PERMANENT storage; all data that needs to be saved goes here

Input/Output Processors (key components inside the computer)

Perform input/output related processing

ROM

Read Only Memory; PERMANENTLY holds the startup instructions for the computer

Transistors

Replaced vacuum tubes, increased processing speed, less expensive (Invented at Bell laboratories)

Storage

Saves data for use later

Ada Lovelace

She is considered to be the first computer programmer. She wrote a computer language for the Analytical Engine.

Process

Takes data performs instructions on it, to change it into the desired informations

Harvard Mark 1

The IBM Automatic Sequence Controlled Calculator was given to Harvard in 1944. (Howard Aiken and Grace Hopper)

CPU Scheduling

The act of determining which process in memory is given access to the CPU so that it may execute

Latency (Disk Scheduling)

The additional time it takes the platter to rotate into the proper position (So data can be read or written)

Difference Engine

The first mechanical computing device; could add, subtract, polynomial functions

disk scheduling

The technique that the operating system uses to determine which requests to satisfy first (which requests to access secondary memory to process first)

1st Generation Computers

Vacuum tubes, relay switches, the need to program in machine language

Shortest-seek-time (disk scheduling techniques)

a request may be ignored for a long time because it has a long seek time

CPU (Central Processing Unit)

an advanced integrated circuit with a large number of pins; computer's brain

Integrated Circuits

chips that contain large numbers of tiny transistors (invented by Jack Kilby)

Input devices

devices which let you enter data into the computer

stylus, game controller, microphone

examples of input devices

monitor, printer, GPS, speaker

examples of output devices

CPU Process

fetch-decode-get data-execute-store

UNIVAC

first commercial computer

RAM (Key components inside the computer)

holds data and instructions for currently running processes

Computer Functions

input, processing, output, storage

Fourth Generation Computers

microprocessor; development of the personal computer; addition of the mouse and handheld devices

Third Generation Computers

modern computers; used integrated circuits; keyboards instead of punch cards; monitors for display

uniprogramming

processor must wait for input/output operations to execute before proceeding

Output Devices

sends data out from the computer to be seen in a human readable way (text, pics, sound)

First come, First serve (Disk scheduling techniques)

simple scheduling algorithm

ENIAC

the first general-purpose electronic computer

Round Robin

the most widely used method of process executing; each process in the queue gets excited for a short period of time

Computer Hardware

the physical parts of computer that can be touched

Microprocessor

thousands of integrated circuits were built on a silicon chip; created by intel corp

Tabulating Machine

used punch cards to store information. It was later used to tabulate the U.S. Census.