The Abacus :

The abacus, a simple counting aid, may have been invented in Babylonia (now Iraq) in the fourth century B.C.

Jacquard Loom :

Babbage Difference Engine, reconstructed by the British Government in 1991 :

The ENIAC :

The size of a cell phone built with Vacuum Tubes :

The IBM 360 :

The PDP-8

The Microprocessor

A computer chip that contains on it the entire CPU
 Mass produced at a very low price
 Computers become smaller and cheaper
 Intel 4004 – the first computer on a chip, more
powerful than the original ENIAC.
 Intel 8088 – used in IBM PC

Famous Quotes about Computers :

“I think there is a world market for maybe five computers.” – Thomas Watson, chairman of IBM, 1943

“There is no reason anyone in the right state of mind will want a computer in their home.” – Ken Olson, President of Digital Equipment Corp, 1977.


Hardware :

Hardware – the physical devices that make up a computer (often referred to as the computer system)

Hardware Core :

CPU (Central Processing Unit)

CPU (machine) cycle – retrieve, decode, and execute instruction, then return result to RAM if necessary
# CPU speed measured in gigahertz (GHz)
# GHz – number of billions of CPU cycles per second

RAM (Random Access Memory) Also called Memory, Main Memory, or Primary Storage
# Measured in gigabytes (GB, billions of bytes) today
# Byte → Character
# RAM is volatile
# Temporary storage for instructions and data

Software :

Programs – instructions that tell the computer what to do
Categories
# Application software – enables you to solve specific
problems or perform specific tasks.
# System software – handles tasks specific to technology management and coordinates the interaction of all technology devices
# Utility software – provides additional functionality to your operating system software

About System Software :

Operating System
– UNIX / Linux
– Windows
– MAC OS
– Palm OS
– Android
– Language Translators
– C, C++, Basic, Java, …
– Device Drivers

About C Programming Language
# Developed at AT&T Bell Labs in early 1970s
# Unix also developed at Bell Labs
# All but core of Unix is in C
# Standardized by American National Standards Institute (ANSI)

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