Computer Terminology Chapter 2 CIT 1100

History of Computers First known device used to compute was the Abacus 3000 BC 1617 John Napier created a crude slide rule referred to as Napier’s Bones First mechanical adding machine was created by Blaise Pascal 1642 Difference Engine is considered the first general purpose computing machine created in 1822 by Charles Babbage

History of Computers Up until the 19 th century all “computers” were mechanical In 1906 Lee De Forest invented the vacuum tube Scientists realized that they could now create an actual electronic computer

History of Computers Vacuum Tubes allowed early engineers to control the flow of electricity The methods needed to represent and store information took another 50 years to resolve During WWII there was a breakthrough

History of Computers Its much easier to communicate with a machine using Binary A single Binary digit has only 2 states – Its either ON – Or Its OFF The only drawback is you can only represent 2 things using Binary digits Decimal can represent 10 things OFFON

6 Bits Two patterns are known as the state of the bit. For example, magnetic encoding of information on tapes, floppy disks, and hard disks are done with positive or negative polarity. The boxes illustrate a position where magnetism may be set and sensed; pluses (red) indicate magnetism of positive polarity (1 bit), interpreted as “present” and minuses (blue) (0 bit)

History of Computers DECIMAL REPRESENTATION BINARY REPRESENTATION Allows you to count to ten using one character (0-9) 01 Allows you to count to 2 using one character (0-1)

Binary The Binary Numbering system is used by computers to represent data People prefer to communicate using Decimal numbering To communicate with hardware you must break everything down to its most basic form BINARY

Decimal We have become familiar with base 10 because that’s the way we have always counted. We have memorized ten characters that represent ten symbols used to represent numbers

Decimal Math Carry

Binary Math

Counting BinaryDecimal

The CPU Central Processing Unit – Input – Processing – Output – Storage

INPUT Switch OFF 0Switch ON 1 Using one piece of wire with one light bulb we can represent 2 different states in Binary ON / OFF

ASCII CHARACTERS In order to create meaningful data on a computer you need the following symbols: Counting Numbers 0-9 Alpha Characters A-Z Alpha Characters a-z Punctuation Special Characters 256 Characters

16 ASCII-7 In the early days, a 7 bit code was used, with 128 combinations of 0’s and 1’s, enough for a typical keyboard. The standard was developed by ASCII (American Standard Code for Information Interchange) Each group of 7 bits was mapped to a single keyboard character. 0 = = = = … 127 =

DATA BUS With one wire you can represent 2 states With two wires you can represent 4 states With three wires you can represent 8 states 2 x = number of possible combinations of 1s & 0s

DATA BUS Using a single bit, with two discrete states, gives only two options (ON or OFF). 1 bit, 2 unique patterns: 0 or 1 2 bits, 4 unique patterns: 00, 01, 10 or 11 4 bits, 16 unique patterns: 0000, 0001, 0010, 0010, … bits, 256 unique patterns: , , , …

Binary

DATA BUS With 8 Wires you can represent 2 8 = 256 unique characters INPUT DEVICE AB a bHK High Order Bit Low Order Bit

21 Byte Byte = A collection of bits (usually 7 or 8 bits) which represents a character, a number, or other information. More common: 8 bits = 1 byte Abbreviation: B

22 Bytes 1 byte (B) Kilobyte (KB) = 1,024 bytes (2 10 ) “one thousand bytes” 1,024 = 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 Megabyte (MB) = 1,048,576 bytes (2 20 ) “one million bytes” Gigabyte (GB) = 1,073,741,824 bytes (2 30 ) “one billion bytes”

Definitions BIT – The smallest piece of data a computer can work with BYTE – 8 Bits BUS – A piece of wire that carries a signal Clock – Used to synchronize evens

Labs Hints Locate & identify the connector that delivers power to the motherboard. Is the connector an AT or ATX style? power-up-an-atx-power-supply/

Labs Hints Molex vs. berg connector? 4 Pin Berg Connector 4 Pin Molex Connector 20 Pin Molex

Labs Hints Does your system support PCI –E slots?

Labs Hints Scan the motherboard for any terminal blocks and jumpers. These numbers are just FYI. Each venders have their own different numbers and purpose reference chart.

Labs Hints What Socket is supported by the system?

Labs Hints North Bridge chip type vs. South Bridge chip type

Labs Hints