computer hardware. what is a computer a data processing machine operated automatically under the...

Computer Hardware Computer Hardware

What Is a Computer What Is a Computer

A data processing A data processing machine operated machine operated automatically automatically under the control under the control of a list of of a list of instructions (called instructions (called a program) stored a program) stored in its main memory.in its main memory.

What Is a Computer What Is a Computer

What Is a Computer What Is a Computer System System

The MicroprocessorThe Microprocessor

- Microprocessor (- Microprocessor (CPUCPU - - C Central entral PProcessing rocessing UUnit)- Computers high nit)- Computers high speed memory, logic, and control speed memory, logic, and control are on a single chip.are on a single chip.– 6 generations of Intel micro processors6 generations of Intel micro processors

8088 (XT), 80286 (AT), 80386, 80486, 8088 (XT), 80286 (AT), 80386, 80486, Pentium (+MMX), Pentium Pro.Pentium (+MMX), Pentium Pro.

all are obsolete with the exception of high all are obsolete with the exception of high end Pentiums and Pentium Pros.end Pentiums and Pentium Pros.


The speed of a microprocessor is The speed of a microprocessor is dependent on 2 things…dependent on 2 things…– the generation of the microprocessorthe generation of the microprocessor– the clock speedthe clock speed

indicates how fast instructions are indicates how fast instructions are processed.processed.

measured in MHz (millions of cycles per measured in MHz (millions of cycles per second)second)


Example:Example:– A 200 MHz Pentium is faster than a A 200 MHz Pentium is faster than a

166 MHz Pentium.166 MHz Pentium.– but how much faster.but how much faster.– how much faster is a Pentium Pro 200 how much faster is a Pentium Pro 200

MHz compared to a Pentium 133 MHz.MHz compared to a Pentium 133 MHz.

ICOMP IndexICOMP Index

To compare current Intel To compare current Intel microprocessors (CPU) we use the microprocessors (CPU) we use the ICOMP index.ICOMP index.– performance index of Intel CPUs.performance index of Intel CPUs.– the higher the number, the faster the the higher the number, the faster the

CPU.CPU.– allows you to purchase the fastest allows you to purchase the fastest

machine you can afford.machine you can afford. Lets take a look at the ICOMP index.Lets take a look at the ICOMP index.

Primary MemoryPrimary Memory

Primary Memory (RAM)- A temporary Primary Memory (RAM)- A temporary storage area that holds data storage area that holds data instructions, results, and passes instructions, results, and passes information back and forth to the CPU.information back and forth to the CPU.– the larger the memory the more the larger the memory the more

sophisticated programs can run.sophisticated programs can run.– more programs can remain in memory at more programs can remain in memory at

the same time.the same time.– the faster the system.the faster the system.


Memory (Memory (RRandom andom AAccessccess M Memory)emory)– made up of individual storage made up of individual storage

locations, each of which holds one locations, each of which holds one character (called a Byte)character (called a Byte)

– A Byte is made up of 0’s and 1’s. Each A Byte is made up of 0’s and 1’s. Each 0 or 1 is called a Bit (0 or 1 is called a Bit (BBinary Diginary Digitit). 8 ). 8 Bits make a Byte.Bits make a Byte.

– 11000001 = 19311000001 = 193


The amount of memory is measured The amount of memory is measured by the # of bytes it can hold:by the # of bytes it can hold:– 1 Kilobyte (KB) = 1,024 bytes1 Kilobyte (KB) = 1,024 bytes– 1 Megabyte (MB) = 1,048,576 bytes or 1 Megabyte (MB) = 1,048,576 bytes or

1000 (KB)1000 (KB) RAM memory is VOLATILE. It is lost RAM memory is VOLATILE. It is lost

as soon as you shut of the power.as soon as you shut of the power.– therefore what….therefore what….


We need an permanent storage We need an permanent storage area.area.

This permanent memory is called This permanent memory is called secondary or auxiliary storage.secondary or auxiliary storage.– types ???types ???

Auxiliary StorageAuxiliary Storage

A permanent storage device that A permanent storage device that retains its contents when the power retains its contents when the power is turned off.is turned off.– hard (fixed) Disk - remains hard (fixed) Disk - remains

permanently inside the system unit. permanently inside the system unit. (uses metal platters)(uses metal platters)

– floppy disk - is portable and is made floppy disk - is portable and is made up of a plastic disk, enclosed in a hard up of a plastic disk, enclosed in a hard plastic case.plastic case.

Auxiliary StorageAuxiliary Storage

Hard disk will hold more data than Hard disk will hold more data than a floppy disk.a floppy disk.

Hard disk space is measured in Hard disk space is measured in Gigabytes (1GB = 1000MB = 1 Gigabytes (1GB = 1000MB = 1 Billion Bytes)Billion Bytes)

Floppy Disk (3.5” Floppy)Floppy Disk (3.5” Floppy)– high Density (1.44 MB)high Density (1.44 MB)– double Density (720 KB)double Density (720 KB)

Auxiliary Storage Auxiliary Storage

CD-ROM - compact disk read only CD-ROM - compact disk read only memorymemory– you can read from the CD but can not you can read from the CD but can not

write to it.write to it.– CD hold approx.. 650MB of data.CD hold approx.. 650MB of data.

CD-Recordable CD-Recordable – allows you to read and write to a CD.allows you to read and write to a CD.

CD-ROM and RecordablesCD-ROM and Recordables

Speeds of CD-ROMs and Speeds of CD-ROMs and recordables are measured byrecordables are measured by– access Time: The average time to find access Time: The average time to find

a specific item.a specific item.– transfer Rate: The amount of data transfer Rate: The amount of data

that is read/secondthat is read/second

CD-ROMs and RecordablesCD-ROMs and Recordables

1st CD-ROMs had speeds of 600 1st CD-ROMs had speeds of 600 millisecond access time and millisecond access time and transfer rates of 150 KB.transfer rates of 150 KB.

Speeds are now up to 32 times the Speeds are now up to 32 times the original speed (32X).original speed (32X).

The Local BusThe Local Bus

The Bus is The Bus is – the circuitry on the motherboard (the the circuitry on the motherboard (the

main board that holds the main board that holds the microprocessor, memory, and adapter microprocessor, memory, and adapter cards) thatcards) that

– provides a path for which data travels provides a path for which data travels from one component to another.from one component to another.

The Local BusThe Local Bus

Today’s PCs have multiple local Today’s PCs have multiple local busesbuses– each Bus is 32bits wide and travels as each Bus is 32bits wide and travels as

fast as the microprocessor. fast as the microprocessor. – each Bus is connected to a specific each Bus is connected to a specific

device and does not have to share it device and does not have to share it with other components.with other components.

– PCI - A bus designed by Intel for the PCI - A bus designed by Intel for the Pentium or Pentium Pro.Pentium or Pentium Pro.

PrinterPrinter

PrintersPrinters– Dot MatrixDot Matrix

lots of noiselots of noise bad Print Qualitybad Print Quality

– Inkjet Inkjet today’s entry level printertoday’s entry level printer quite and pretty good speedquite and pretty good speed

– LaserLaser top of the linetop of the line quality measured in PPM and DPI.quality measured in PPM and DPI.

ModemModem

Connects you computer to the Connects you computer to the outside worldsoutside worlds

Modulate - Converts a digital signal Modulate - Converts a digital signal into an analog oneinto an analog one

Demodulate - Converts an analog Demodulate - Converts an analog signal to a digital one.signal to a digital one.

ModemModem = = MoModulate dulate demdemodulateodulate ExampleExample

ModemModem

Speed is measured in BPS (Bits per Speed is measured in BPS (Bits per second)second)

Standard speed today is 28,800 BPS Standard speed today is 28,800 BPS (28.8 KBPS) to 33,600 BPS (33.6 KBPS)(28.8 KBPS) to 33,600 BPS (33.6 KBPS)

Today the standard is a FAX/MODEM Today the standard is a FAX/MODEM where you get the functions of a where you get the functions of a MODEM and a FAX machine on one MODEM and a FAX machine on one card.card.

Sound CardSound Card

2 Functions2 Functions– play previous recorded sound play previous recorded sound

(translates a digital file into sound)(translates a digital file into sound)– to record new sound (translate sound to record new sound (translate sound

into a digital file)into a digital file) Need good speakersNeed good speakers Every sound card has at least 2 Every sound card has at least 2

chipschips

VideoVideo

2 major components2 major components– monitormonitor– display Adapter (Video Card)display Adapter (Video Card)

MonitorMonitor– pixelspixels– dot pitchdot pitch– vertical refresh ratevertical refresh rate

Monitor QualityMonitor Quality

PixelsPixels - ( - (PICPICture ture ELELementementSS))– the number of dots that make up a the number of dots that make up a

picturepicture– measured bymeasured by– # of dots across X # of dots across X # of dots down# of dots down

800800 X X 600600

– in this example the max number of in this example the max number of pixels that can be displayed on any pixels that can be displayed on any monitor is 800 X 600 = 480,000monitor is 800 X 600 = 480,000


This formula (Pixels across This formula (Pixels across XX Pixels Pixels down) is called the resolution.down) is called the resolution.

The bigger the monitor the larger The bigger the monitor the larger the dots and the easier it is to see the dots and the easier it is to see the imagethe image

The higher the resolution the The higher the resolution the sharper the image.sharper the image.

But…But…


What happens when...What happens when...

– small Monitor and High Resolutionsmall Monitor and High Resolution 14” 1280 X 1024 (1,310,720)14” 1280 X 1024 (1,310,720)

– large Monitor and Low Resolutionlarge Monitor and Low Resolution 20”20” 640 X 480 (307,200)640 X 480 (307,200)

Need a balance between resolution Need a balance between resolution and monitor size.and monitor size.

Resolution and Monitor Resolution and Monitor SizeSize

MinResolution Pixels Screen

Size

640 X 480 (VGA) 307,200 14”800 X 600 (Super VGA) 480,000 15”1024 X 768 (Extended VGA) 782,462 17”1280 X 1024 1,310,720 20”


Dot PitchDot Pitch - - – distance between adjacent Pixelsdistance between adjacent Pixels

The smaller the dot pitch the The smaller the dot pitch the crisper the image (good) the crisper the image (good) the smaller the dot pitch the more smaller the dot pitch the more grainy the image (bad).grainy the image (bad).

Get a monitor with a dot pitch less Get a monitor with a dot pitch less than .28 mm.than .28 mm.


Vertical refresh rateVertical refresh rate – how fast the screen is repainted how fast the screen is repainted

(refreshed) from top to bottom(refreshed) from top to bottom If it is too slow the screen will If it is too slow the screen will

flicker. flicker. Get 70MHz (70 cycles per second) Get 70MHz (70 cycles per second)

or faster. or faster.

Display AdapterDisplay Adapter

Display (video) adapter - accepts Display (video) adapter - accepts info from the CPU and sends it to info from the CPU and sends it to the monitor to display the imagethe monitor to display the image– get one with an accelerator chip. The get one with an accelerator chip. The

video card will have its own processing video card will have its own processing chip. Freeing up the CPU to do other chip. Freeing up the CPU to do other things.things.

– the video card should also have its the video card should also have its own memory (at least 1 MB). own memory (at least 1 MB).

SummarySummary

History of computersHistory of computers Microprocessors.Microprocessors. Primary and second memory.Primary and second memory. The local bus.The local bus. Other hardware such as printer, Other hardware such as printer,

modem, sound card, monitor display modem, sound card, monitor display etc. etc.

Next lecture on computer software.Next lecture on computer software.

computer hardware. what is a computer a data processing machine operated automatically under the...

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