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PC: History and Tech. Definitions.

PC is short for Personal Computer, a desktop or laptop size device that is in the center of the information, communication and automation revolution continuing today.

A Little History

Concepts found in computer design and operation today came through the ideas and inventions of Charles Boole, Blaise Pascal and Charles Babbage hundreds of years ago.

Bell Laboratories built the first "modern" computer for the U.S. Government in 1940 using electromechanical relays. The first general-purpose computer was developed jointly by Harvard University and IBM using relays and vacuum tubes in 1952. The first commercially available general-purpose computer was the UNIVAC developed by the Sperry Corp.

These first computers were the size of a small house or a large room (the "laptop" models). Bell Labs invented the first Solid State Switch (the transistor) in the early 1950's which started the trend towards smaller yet more powerful computers we still see today. Using transistors instead of relays and vacuum tubes reduced the size of computers (and the electrical power supplied) by a factor of 10!

In the mid 1970's the Intel Corp. developed the Microprocessor which put thousands of interconnected transistors on a Silicon Chip less than one half square inch in area. This advance allowed the MITS Corp. to offer to the general public the Altair 680, the first personal desktop computer

Tech. Definitions

ASCII	American Standard Code for Information Interchange - A world recognized code that allows letters, numbers, punctuation marks, symbols and special commands to be sent from one computer to another.
Basic	A high level programming language that is easy to use and understand.
Binary	The name of the smallest/ shortest/ simplest number system made up with only 2 possible number characters (0 and 1). All computers process data in binary form.
BCD	Binary Coded Decimal - A standard code to send, store and receive decimal numbers in binary form.
BIT	BInary digiT - a single memory cell in a computer holding a 0 or 1. Groups of bits make up data like ASCII or BCD.
Boot	A short program usually running on power up that sets up the computer. Example: Check memory, battery, drives, and load DOS.
BUSS	A set of connections inside the computer that link the parts together. Example: Microprocessor to memory to floppy drive to keyboard to CRT etc.
Clock	With respect to computers, a Clock tic is what triggers the next instruction and allows the CPU to step through the program. Even a slow computer click will tick fast enough to allow thousands of instructions to be executed every second.
CPU	Central Processing Unit - An area of the Microprocessor that controls what instructions to decode and execute and any math or logical functions.
Disc	A disk of magnetic material that can store data as a series of bits.
EEROM	Electrically Erasable Read Only Memory (See ROM).
EPROM	Erasable Programmable Read Only Memory (See ROM).
HEX	Hexadecimal - A number systems with 16 characters that can be directly related to binary.
Input	Data or signals going into a computer system for storage or processing.
Octal	A number system with 8 characters that can be directly related to binary.
OS	Operation System - A controlling program constantly running in a computer that is loaded at boot up. Most computers run MS-DOS (Micro Soft Disk Operating System).
Program	All computers would do nothing without a program of instructions - the software. This is what is in memory to tell the computer what to do next.
RAM	Random Access Memory - A memory chip that allows a read or write to any memory area using a specific address. RAM chips need a constant source of power to hold data.
WORD	In a computer, a word is a set amount of bits that can be stored or processed at one time, usually 8, 16, or 32 bits.

Requirements for a computer

There are seven main requirements for a computer:

1: Power 2: Input 3: CPU 4: Clock 5: Program 6: Memory 7: Output

Computers can be found almost anywhere. Look on your wrist, on your desk, in your car, around your home, etc. The microchip (CPU plus memory) can even be found in musical greeting cards!