Safety

Outcomes Potential health hazards when working with

computer equipment.

Precautions to take to prevent injuries.

Steps and techniques for preventing ESD damage to computer equipment.

Proper grounding of computer equipment.

Electromagnetic interference (EMI).

Do Turn off __________ before dismantling

and unplugging Touch __________ to discharge static

electricity Make sure you know what you are

doing Wear an __________ wrist strap Use __________ that are surge protected Use proper __________ Always heed warning labels

Don’t Attempt to __________ things without

knowledge of computers __________ or __________ near computer Exert excessive __________ on components Open power __________ or monitor Use __________ (screwdrivers, pliers) Touch components by their __________

contacts Leave power bar on __________ OR near

__________ materials.

Electrostatic Discharge(ESD)

Electrostatic Discharge (ESD) ESD is __________ flow between two objects

with different electrostatic potential If no safe path is provided for this flow to

occur, energy is released in the form of a __________ (or shock) as the two objects get closer.

__________ potential is constantly generated by every move we make

The human body will notice discharges above 2000 Volts a much smaller __________ may damage

electronic components

Electrostatic Discharge (ESD) All integrated circuits (ICs) or

“__________" are very sensitive to ESD __________ and CMOS chips are

especially vulnerable Damage may occur even when you

don't feel it. There are 2 types of damage that can

occur Immediate failure Latent failure

Immediate Failures

failures that occur __________ after the chip has been damaged

usually aren't recoverable until the chip has been replaced

Latent Failures

Sometimes a chip can be damaged by electrostatic discharge and the results aren't immediately noticeable Months later the chip could finally

__________ completely May end up with intermittent failures that

occur __________

ESD Protection

Antistatic Wrist Straps Fits on your wrist or is attached to the

case or an __________ mat  Antistatic Mats

provide a __________ surface on which to work or place components as you remove them

Some have a cord that can be plugged into a wall outlet to slowly remove any __________ charges

ESD Protection continued Don't work on a computer or components when

they are __________ Cold, dry conditions promote __________ electricity

Keep components and expansion cards inside their anti-static __________ until you are ready to use them handle them carefully, by their __________ and as little as

possible Before you start working at the computer, touch the

metal __________ to neutralize any potential static build-up

You may also use anti-static __________ on the floor surrounding the area where you are working

Review Also, see “check your understanding” Unit 1

Electrical Fires

Class C Fire Extinguisher Class A - Wood, paper, cloth, trash and

plastics. Solid combustibles that are not metals

Class B - Flammable __________ : gasoline, oil, grease and acetone. Any non-metal in a liquid state, on fire

Class C - __________ : computers and printers. As long as it's "plugged-in," it would be considered a class C fire

Class D - __________ : potassium, sodium, aluminum and magnesium

Electromagnetic Interference EMI

EMI commonly produced by __________ motors,

loudspeakers, electrical lines, radios and cellular phones

can prevent proper transmission of __________ through network cables can cause the PC to __________ when attempting

to communicate with other parts of the network Similar problems could occur if a __________

source is placed too close to a monitor

EMI vs ESD

EMI is recoverable or can be fixed Removing the source of __________ will

correct EMI ESD damage normally results in

components having to be __________

Safe Work area A table top approximately 1x1.5 meters is

usually sufficient an __________ mat for the technician to

stand on, or for the computer case sit on (depending on the model)

adequate lighting Testing equipment tool kit containers for storing components, screws,

etc. (egg cartons work) Shelves and storage cabinets first-aid kit Class ___ fire extinguisher

Warranties

Pay attention to warranty documents A manufacturer may __________ the

warranty if unqualified personnel work on it

They might even void the warranty if anyone, other than the company's own technicians, opens the __________

History of Computers

What is a computer?

A computer is a _______________ for manipulating data according to a list of instructions

Can be electronic, mechanical, or a combination of both

17th Century – Napier’s Bones John Napier

developed a set of calculating sticks called Napier's Bones.

strong influence on the development of the _______________

Napier's Bones reduced ___________ to a sequence of simple additions;

17th Century – Slide Rule slide rule was

invented by the English mathematician William Oughtred

a set of rotating discs, which were calibrated with ______________ logarithms

used commonly (in a linear array) until the early 1970s

17th Century - Calculating Clock the first mechanical

_____________ was designed by Wilhelm Schickard in Germany

___________ logarithms were utilized by rotating cylinders into a large machine housing

17th Century – The Pascaline first

______mechanical calculator was invented by the French mathematician and philosopher Blaise Pascal

Called the ________________

Pascaline

19th Century In 1822, Charles Babbage completed his

_______________, a machine that could be used to perform calculations of simple tables.

The _______________was a complex assembly of wheels, gears and ratchets engineered to exacting specifications.

It laid the foundation for Babbage to design his Analytical Engine Close up

The Analytical Engine a general-purpose device that was to be capable of performing any

type of mathematical _______________. The plans of the analytical engine were the first clear conceptualization

of a machine that could perform the type of computations, which are now considered at the heart of _______________.

Babbage never built his analytical engine, but its design influenced all modern digital computers that were to follow.

The analytical engine was finally built by a team of engineers in 1989, over a hundred years after _______________death in 1871.

For his insight, Babbage today is known as the "father of modern ___________."

20th Century - Eniac The US-built ENIAC (__________________________) was the first electronic

general-purpose computer. It was _________ times faster than its contemporaries. ENIAC's development and construction lasted from _____ to full

operation at the end of _______. When its design was proposed, many researchers believed that the

thousands of delicate valves (i.e. __________) would burn out often enough that the ENIAC would be so frequently down for repairs as to be useless.

It was, however, capable of up to ____________ of operations per _______________ for hours at a time between valve failures.

It publicly validated the use of electronics for large-scale ________________. This was crucial for the development of modern computing.

A “______________" on the ENIAC, however, was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that evolved from it.

To program it meant to ____________ it. (Improvements completed in 1948 made it possible to execute stored programs set in function table memory, which made programming less a "one-off" effort, and more systematic.)

ENIAC

20th Century - ALTAIR The MITS Altair 8800 was a microcomputer design from

1975, based on the Intel 8080 CPU and sold as a _______________ through advertisements in Popular Electronics, Radio-Electronics and other hobbyist magazines.

The designers intended to sell only a few hundred to hobbyists, and were surprised when they sold _______________ in the first month.

The first programming language for the machine was Microsoft's founding product, Altair _______________.

20th Century In ________, the personal computer (____) started

making its way into homes, Market competition between manufacturers, such as

_____ and __________ Computer, led to rapid advances in the field.

For the first time, high-level ____________ ability was in the households of hundreds of thousands of people, rather than a privileged few.

Computers had finally become _______ of the common people.

The personal computer revolution gained momentum when IBM introduced its first personal computer.

The strength of IBM's ___________ was a key factor in legitimizing PCs for general use.

IBM – _____________________________________ (sold calculating machines) The first IBM PC was a __________-based system, which used Intel's

8088 microprocessor. It had no harddrive! The original units had ________________ displays; true graphics were an option that

came later. ____________ was also limited, typically only 128K or 256K of RAM. The machine used an operating system known as ________; a command line system

similar to the earlier CP/M system. IBM later released the IBM PC/XT. This was an expanded machine that added a

_____________ and CGA graphics. As the machine became popular, several other companies began to

release imitations of the IBM PC. These early “_______________" were marked by incompatibilities owing to

their inability to properly reproduce IBM's BIOS. These were commonly marketed as "90% compatible." This problem would soon be overcome, and the resulting competition would serve to push technology and drive prices down.

___, __________, ___________, etc. are all IBM “Clones”

20th Century Cont’d

20th Century – MS-DOS 1981 also saw the emergence of MS-DOS

(developed by Microsoft), a ____________ OS Stands for “________________________” was the dominant operating system for the PC

compatible platform during the 1980s. It has gradually been replaced on consumer

desktop computers by various generations of the _________________ operating system

20th century cont’d Apple Lisa

Appeared in 1983 and was named after Steve Jobbs’ ____________

It was the first personal computer with a GUI (____________________).

Aimed at the ________ world

Macintosh More affordable,

_______________ computer 1984

Windows 1985, Windows served

as an ________ to MS-DOS

It was an actual program that ran within ______ in order to provide a gui

Windows 95 appeared in 1995 and was a self-contained ____________

It was ___________ by Windows 98, then Win XP, the unpopular Windows Vista, and currently Windows 7.