Memory Updated


3/28

Read Only Memory (ROM)Read Only Memory (ROM)

The data in this chips can only be readand used it cannot be changed sothe memory is called read only

memory (ROM). It contains a set of start up

instructions that check to see that the

rest of memory is functioningproperly, check for hardware devices,and check for an operating system onthe computers disk drives.


4/28

Random Access Memory (RAM)Random Access Memory (RAM)

It is a chip designed to store data

temporarily. It also serves as a scratch

pad where processed and still

needed data by the CPU is temporarily

stored.

It is available in a single chip that can

be placed directly in the system board.


5/28

Other Parts thatOther Parts thatContribute toContribute to

SpeedSpeed

Performance ofPerformance ofthe Computerthe Computer


6/28

Virtual RAMVirtual RAM

The most important and much needed

part of the program are placed in the

RAM, while the least important areplaced in the reserved part of the hard

disk that function as a temporary

storage of programs or virtual-RAM,better termed as virtual memory.


7/28

Virtual Ram


8/28

Computer BusComputer Bus

Data BusData Bus is an electrical path that

connects the CPU, memory, and the

other hardware devices on themotherboard.

Address BusAddress Bus is a set of wires similar

to the data bus that connects the CPUand RAM and carries the memory

addresses.


9/28

Computer Bus


10/28

System ClockSystem Clock

It is driven by a piece of quartz crystal.

When electricity is applied, the molecules

in the quartz crystals vibrate millions oftimes per second, a rate that never changes.

The speed of the vibration is determined by

the thickness of the crystal.

The computer uses the vibrations of the

quartz in the system clock to time its

processing operations.


11/28

Ports


12/28

Expansion Slots


13/28

Hardware InterfaceHardware Interface

Special hardware components needed

for communication between an

Input/Output device and theMicroprocessor Unit.

It converts the data from a form used

by any of the I/O devices to a from

acceptable by the other device.


14/28

Video Interface Card


15/28

Major Differences of CentralMajor Differences of Central

Computer and PeripheralsComputer and Peripherals

Peripherals orI/O devices areelectromechanical devices and theirmanner of operation is different from the

operation of the CPU and memory whichare electronic devices. Therefore, aconversion of signal values may berequired.

The data transfer rate of peripherals isusually slower than the transfer rate of theCPU. Consequently, a synchronization

mechanism may be needed.


16/28

Data codes in each device differ from

the word format in the CPU andMemory.

The operating modes ofI/O devices

differ from each other and must be

controlled in a way that does not

disturb the operation of other devices

connected to the CPU.


17/28

Small Computer System InterfaceSmall Computer System Interface

One device interface that takes adifferent approach and overcomingthe constraints of a limited number ofexpansion slots on the motherboard.

Instead of plugging cards into thecomputers bus via the expansionslots, SCSI extends the bus outside thecomputer by the way of a cable.


18/28

Serial and Parallel PortsSerial and Parallel Ports

Serial InterfaceSerial Interface data bits are transmitted one at

a time through a single wire.

Serial PortsSerial Ports are most often used to connect a

mouse or a modem. Parallel InterfaceParallel Interface can handle a higher volume

of data than a serial interface, because more than

one bit can be transmitted through a parallel

interface simultaneously. Parallel portsParallel ports are most often used for printer

interfaces, although some other products use

them as well.


19/28

Serial Ports

Parallel Ports


20/28

Universal Serial BusUniversal Serial Bus

It allows a wide variety of computer

peripherals to be easily connected to most

Windows 98/2000 PCs, and Apple iMac/G3/G4 computers.

It provides far superior data transfer speeds

(up to 100 times faster) when compared tothe 25-pin parallel and DB-9 serial & DB-

25 RS-232 serial ports found on most

computers.


21/28

Universal Serial Bus


22/28

Expansion Slots and BoardsExpansion Slots and Boards

Extensions of the computers bus thatprovide a way to add new components

to the computer.

The slots accept circuit boards, alsocalled cards, adapters or just boards.

Modern notebook computers are toosmall to accept the same type of cardsthat fit into the desktop models.


23/28

Expansion Board


24/28

Purposes ofExpansion SlotsPurposes ofExpansion Slots

To give built-in devices such as harddisks and diskette drives access to thecomputers bus via controller cards.

To provide I/O (input/output) ports onthe back of the computer for externaldevices such as monitors, external

modems, printers, and the mouse.

To give special purpose devicesaccess to the computer.


25/28

Prepared by Group 2


26/28

Cammylflor OrayaLeader

Jerryle Alexies AquinoMember


27/28


28/28

Thanks for Listening

Documents

Memory Updated