MICROPROCESSOR:
The microprocessor is the mind of any computer. It controls all sports inside the laptop. It plays two varieties of operations – arithmetic & logical process (internally) and examine & write (externally). Read /write operations are performed on two kinds of gadgets – I/O and reminiscence devices. It uses the “deal with the bus” to select any “vicinity” on those devices, sends a examine/write sign over the “manage bus,” and then the statistics over the “records bus”.
MEMORY DEVICES:
The CPU shops all information inside the computer’s memory. There are reminiscence types – RAM & ROM.
RAM (Random Access Memory):
This unstable type is an examine-and-write memory tool. This loses its contents while the power is shut off.
The forms of RAM are
· DRAM (Dynamic RAM) – is similar to a capacitor, as it tends to lose its contents and requires refreshing. This is the Computer RAM.
· SRAM (Static ram) – Is quicker than Dram and does not require to be refreshed. This is steeply-priced; therefore, a restrained amount is best used as CACHE reminiscence within the PC.
ROM (Read the best reminiscence):
ROM may be programmed using a programmer and acts as an “examine best” tool. This device is used because the textbook for the CPU in the computer is referred to as ROM BIOS. It stores all the fundamental facts of programming the device’s gift within the system in addition to the POST (Power On Self Test) series. AMI BIOS and AWARD BIOS are the most commonplace ROM BIOS.
The kinds of ROMs are
· PROM (Programmable Read Only Memory)
· EPROM (Erasable & Programmable Read Only Memory)
· FLASH ROM
· EEPROM (Electrically EPROM)
· EEPROM (Electrically Alterable ROM)
I/O DEVICES:
Apart from passive memory gadgets, there are sure controllers in the device, which assist the CPU in performing numerous operations. These are called I/O devices. These devices consist of an Interrupt controller, Timer, Ports, DMA Controller, Floppy Drive Controller, CRT Controller, etc.
BUSES & EXPANSION SLOTS:
These are the methods through which communication among numerous computer devices takes place, and the sorts are noted below.
ISA (Industry Standard Architecture):
ISA bus includes a 24-bit address bus and a 16-bit facts bus. ISA can help 8MHZ clock velocity.
MCA BUS (Micro Channel Architecture):
MCA bus is available both in 16-bit or 32-bit variations. It evolved into a new line of computers called the PS/2 (private gadget 2). The clock velocity is slightly quicker (10MHZ as opposed to 8MHZ).
EISA BUS:
EISA has a 32-bit Address and Data bus and 10MHZ CLK velocity.
VL BUS/VESA LOCAL BUS:
It is a 32-bit bus that became positioned local to the CPU and its call. Therefore, it can assist high bus speeds (that of the CPU).
PCI BUS:
PCI has many benefits over different bus types. First of all, it helps sixty-four-bit and 32-bit statistics paths. So it could be used each for 486 and Pentium primarily based systems. PCI can run up to 33MHZ speed and be removed from the CPU. INTEL advanced this bus.
PCMCIA (PC Memory Card International Association):
The PCMCIA was first designed to increase the reminiscence in small, handled computers. PCMCIA bus width is only sixteen bits. However, a 32-bit version is coming. There are three forms of playing cards, specifically
· Type 1 (3. Three m thick)- used for reminiscence card.
· Type 2 (5 mm thick)- used for modem and LAN adapter.
· Type three (10. Five mm thick) – used for most common programs like PC tough disk Cards.
ADD-ON CARDS:
These are cards plugged directly into the principal board, the motherboard (The one that homes the CPU & RAM/ROM Bios). Each performs unique capabilities of interfacing the Motherboard to the peripheral tools like the mouse, Monitor, etc. Some Add-ons are discussed below.
DISPLAY ADAPTER:
These interface the Motherboard with the screen, and there are several kinds of cards. The versions are in resolution, no of shades supported, and pace.
CGA (Color Graphics Adapter)
640 X 200 pixels
MDA (Mono Display Adapter):
Eighty characters wide, 25 strains long
EGA (Enhanced Graphics Adapter):
640 X 350 mode
VGA (Video Graphics Adapter):
Advanced versions of SVGA/TVGA which begin from a resolution of 640 X 480 pixel
AGP (Accelerated Graphics Port):
Introduced in the Celeron/P II-based systems, this caters to the worrying multimedia applications with excessive overall performance.
IDE I/O CARD:
Supports the following functions.
SERIAL PORT:
Communication outside the laptop is completed serially (bit after bit) through this port. It connects conversation gadgets like the mouse, modem, and so forth.
PARALLEL PORT:
Eight Bit facts transfer takes region between the computer and an outside tool. It is usually used to connect a printer.
GAME PORT:
It is used to attach a joystick for gambling video games.
IDE (Integrated/Intelligent Drive Electronics) Interface: This interface is used to speak with IDE Hard disks.
FLOPPY DISK CONTROLLER:
The FDC can aid up to two floppy disk drives. The FDC is attached to the system bus and the DMA controller. It performs records transfer in DMA mode.
SOUND CARD:
This card provides audio consequences to the PC by offering a microphone and speaker interface. This is used in Multimedia Computers.
PERIPHERAL DEVICES:
FLOPPY DRIVES:
1. Forty-four MB & 1.2 MB are forms of popular Floppy Drives.
HARD DISK DRIVES:
ST 506 & ESDI are vintage types. IDE tough disks are famous because their price-to-performance ratio is excellent. SCSI (Small Computer Systems Interface) is the best alternative for very high overall performance if a charge isn’t a criterion.
CDROM DRIVES:
CDROM power is utilized in a multimedia system as it could help all styles of CD ROMs – be it statistics CD, Audio CD, or Video CD. It has the advantage of storing about 650 MB of facts in an unmarried CD.
KEYBOARD:
The keyboard interprets the keystrokes into letters or numbers. These letters are analyzed, and the computer CPU executes instructions on what was sent. Variations in phrases of XT/AT, no. Of keys, the sort of keys used can be located.
MOUSE:
To interact with the pix (ICONS), a special pointer device becomes brought into the laptop world. This tool is a mouse and is hooked up to the serial port.
The mouse incorporates a round ball that makes touch with rollers: one for the X-axis (the horizontal) and one for the the Y-axis (the vertical). Moving the mouse causes the ball to roll, and the ball in touch with the two rollers causes them to show. This is used for shifting; clicking the mouse buttons makes a pointer head at the display screen and choice.
SCANNERS:
In addition to keyboards and pointing devices, there may be some common approaches to getting facts into the PC. A Scanner is used to test a photograph (say from a picture), and enhancing may be done without using a suitable software program.
MONITORS:
The Monitor receives video indicators from the PC video adapter card and shows the video information as pixels (image elements) on the display display screen. Form of monitors from CGA mono to SVGA color is available for customers to pick from (though the previous is completely obsolete).
CONFIGURATION SETUP:
This is in which we outline the device configuration. This is completed handiest when the machine is assembled and configured for the first time or while it’s far upgraded. (One might also enter the SETUP by pressing the the “Del” key because the gadget is powered up). Different BIOS support one-of-a-kind alternatives; however,, the most vital ones observed on all systems are indexed below.
DATE & TIME: It shows the perfect Date and time. It needs to be set when the get is first established.
FLOPPY TYPE:
To outline the Floppy drives connected (1.2MB or 1.44MB).
HARD DISK TYPE: Select the Hard disk kind (Primary or secondary)
DISPLAY TYPE: It picks the forms of video adapter used for the gadget reveal.
CACHE ENABLE/DISABLE:
This class quickens the Memory access. (Default price: Enable) and defines the presence or absence of cache memory.
QUICK POWER ON SELF TEST: It quickens the Power On Self Test once you energy up the PC.
PASSWORD SETTING: This lets you set the System password.
POWER MANAGEMENT: This category allows you to pick out the type (or diploma) of power saving.
LOADING DEFAULT VALUES:
Many parameters want to be described within the CMOS setup, and one won’t want to achieve this manually. This choice masses certain default values, saved inside the BIOS ROM, that have been defined using the producer for the p of the line system performance.
TURN ON/OFF ONBOARD FUNCTIONS:
To turn on/off, onboard functions like Floppy Disk Control and so forth (This applies handiest to included Motherboards in which the ADD ON features are retained on the Motherboard itself).
PNP FEATURES: This class is used to configure the PCI Bus slots.
IDE AUTO DETECTION: This robotically lets you stumble on the IDE Hard drives.
SAVING & EXITING:
This permits you to keep the brand new, valuing the CMOS reminiscence and preserving with the booting procedure.
POST (POWER ON SELF TEST):
This POST firmware is stored in ROM at the Motherboard. This POST is a series of simple software to check and catch faults in different components and circuits. It assesses the microprocessor, interrupt controller, PPI, DMA controller, ROM, RAM, peripheral controllers, etc.
SYMPTOMS:
In case of mistake detection, all through POa ST, indications like error beeps/mistake messages help troubleshoot troubles.
SPEAKER:
With the help of speaker error beeps, we can troubleshoot faults. Each fault causes the speaker to emit distinct patterns of beeps.
DISPLAYED ERROR MESSAGES:
When the get is powered on, an Iran error message may be displayed on the screen (Floppy disk fail) if the Video Adapter is functional.
DIAGNOSTIC CARDS:
The superior diagnostic add-on card captures details of POST collection and displays a hexa code, which can be used for in-intensity & accurate prognosis of a POST problem.
CDROM DRIVES:
A PC CD-ROM force uses small, interchangeable, plastic-encased discs from which facts are retrieved using a laser beam, similar to a music disc. And like a tune CD, a computer CD-ROM shops massive amounts of statistics. This is done by using mild to file data in a form that’s more tightly packed than the highly clumsy magnetic examine/write heads a traditional force needs to manipulate.
The force is controlled by software on your PC that sends commands to controller circuitry. It is either a part of the computer system’s motherboard or on a separate board installed in an expansion slot.
How does a CD_ROM pressure work?
· A motor continuously varies the fee at which the CD-ROM disc spins so that regardless of where a thing, known as a DETECTOR, is positioned about the radius of the disc, the portion of the disc at once above the detector is continually on the equal speed.
· The laser initiatives a focused beam of mild similarly centered by a focusing coil.
· The laser beam penetrates a protective layer of plastic and moves a reflective layer that looks like aluminum foil on the lowest disc.
· The floor of the reflective layer alternates between lands and pits. Lands are flat floor regions; pits are tiny despair in the reflective layer. These surfaces are files of the 1s and 0s used to shop facts.
· Lights that move a bit scattered. But mild that strikes land is contemplated without delay returned on the detector, passing through a prism that deflects laser beam to a LIGHT-SENSING DIODE.
· Each pulse of mild that moves the mild-sensing diode generates small electric voltages. These voltages are matched in opposition to a timing circuit to generate a stream of 1s and 0s that could be recognized.
