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.