Notes- HARDWARE

TextNotes- HARDWARE

A computer is defined as a machine that:

1. Accepts input - Input devices

2. Processes data -- C.P.U.

3. Stores data -- R.A.M.

4. Produces output -- Output devices

Input devices = Keyboard, Mouse, Floppy Drive, Scanner, Bar Code Reader, etc.

C.P.U. = Central Processing Unit (Intel Inside) vs. AMD

The speed of the c.p.u is measured in hertz:

A. Clock speed (mhz) 500mhz , 800 mhz , (1000 mhz = 1 gigahertz ) , 2 ghz

Bus= internal pathway

R.A.M. (Measured in Megabytes) R.A.M. random access memory = "working memory" .. More is better !! 32megs - 64 megs - ?? R.a.m. fluctuates in price.. It is easy to upgrade your computer and add RAM.

Output devices = Monitor, Printer, Fax

Computer Sizes:

Supercomputers = Trillions of calculations per second.

Mainframes – Government/ Large business size.

Microcomputer – Home – Small business. (200 million calculations per second)

Notebook – Small – Light

Palmtop – Very small – Difficult to use.

Two major Microcomputer Platforms:

MS- DOS AND Mac (Not truly compatible but certain SOFTWARE products are CROSS PLATFORM.)

Network = Connecting several computers together to "share" information.

Internet = One large network

G.U.I. = Graphical User Interface = pictures and graphics that make the screen "Friendlier."

The original interface has a prompt:

C>
CD\
CD Office
CD Word
Word.Exe

Early computers can be classified by their hardware components:

First generation – 1951 Vacuum tubes – Large – Needed cooling

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Second – 1956- Transistors – Smaller – More reliable

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Third – 1966 – Integrated circuits – On a silicon chip.

Fourth – 1969 – Microprocessor = Complete computer on one chip

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Embedded computers are becoming more common in appliances, automobiles, and military weapons

Implications: Ease of use, efficient, cost effective

Therefore, "computers" are being integrated into our everyday products.

Will they be embedded in people?

"PARTS IS PARTS"

The SYSTEM UNIT contains all of the essential components:

The MOTHERBOARD ( SYSTEM BOARD ) is the main part of the system. It contains the PROCESSOR, RAM, EXPANSION SLOTS and many other goodies.

ALL other parts are called PERIPHERALS:

When you buy a peripheral ( scanner, printer, digital camera) you need to know what TYPE of CONNECTOR it uses: Keep in mind that each connector has a unique shape and they are NOT interchangable.

Parallel - The PARALLEL port on your computer accepts a 25 pin connector - Most printers are connected to the parallel port.

Serial - The SERIAL port is very similar -

USB - a newer port used to connect peripheral devices. Scanners, printers, digital cameras are commonly connected to the USB port

FIREWIRE - a very new connector that allows for faster transfer of data.

Output from the computer is generally classified into two categories:

1. Soft copy = output goes to monitor, disk, modem, etc.

2. Hard copy = output goes to the printer.

Audio ouput has improved: early computers had one internal speaker that "beeped". You can now add sound cards to the computer that play cd quality sound. You can also run the sound through a home stereo system. Ex: sound blaster card.

New video cards have memory on them to allow better graphics (accelerator cards) newer cards are also called 3-d cards.

There are significant differences between monitors themselves.. The quality (resolution) of the monitor depends on two things:

1. Dot pitch = distance between pixels (less is better)
2. How many pixels there are 400 x 600 or 1280 x 760

Hard drives hold the programs while the computer is off. This "closet" can hold a certain amount of information.. Typical sizes are 2 or 3 gigabytes. ( 30 , 40 gb ) Hard drives (like ram) are easily upgradable. .

Modems allow one computer to communicate with another over phone lines.. Modems are basically the same.. The one important difference is speed.. This is measured in baud (bits per second)

These have also evolved from 300 baud to 1200 to 9600 to 14400 to 28800 to 56,600

DSL and Cable modems are 10 –15 times faster..