Peripheral Component Interconnect (PCI)

PCI (Peripheral Component Interconnect) is a type of computer bus for attaching or inserting peripheral devices into a computer. The PCI standard was first proposed by Intel in 1990 and was widely implemented in computers by 1995. PCI allows for 32- or 64-bit bus specification. PCI is described as high-bandwidth and processor-independent data path between the CPU and high-speed peripherals. PCI uses all active paths to transmit both address and data signals, sending the address on one clock cycle and data on the next. The PCI specification defines two different card lengths. The full-size PCI form factor is 312 millimeters in long; short PCIs range from 119 to 167 millimeters in length to fit into smaller slots where space is an issue.

Micro Channel Architecture (MCA)

The Micro Channel architecture consists of an address bus, a data bus, an arbitration bus, a set of interrupt signals, and support signals. It uses synchronous and asynchronous procedures for data transfer between memory, I/O devices, and a controlling master. The controlling master can be a DMA controller, the system master (system processor), or a bus master. The features of the Micro Channel architecture are:

•I/O data transfers of 8-, 16-, 24-, or 32-bits within a 64KB address space (16-bit address width).

•Memory data transfers of 8-, 16-, 24-, or 32-bits within a 16MB (24-bit address width) or 4GB (32-bit address width) address space.

•A basic transfer procedure that allows data transfers between masters and slaves.

•Interrupt sharing on all levels.

•A flexible system-configuration procedure that uses programmable registers.

•Support for audio signal transfer (audio voltage-sum node).

•Support for both synchronous and asynchronous data transfer.

•An exception condition reporting procedure.

•Improved electromagnetic characteristics.

Extended Industry Standard Architecture (EISA)

EISA is a bus standard for IBM compatible computers. EISA extends the AT bus to 32 bit and allows more than one CPU to share the bus. It was much favored by manufacturers due to the proprietary nature of MCA.

Key features of the EISA bus:

ISA Compatibility: ISA cards will work in EISA slots.

32 Bit Bus Width: Like MCA, the bus was expanded to 32 bits.

Bus Mastering: The EISA bus supports bus mastering adapters for greater efficiency, including proper bus arbitration.

Plug and Play: EISA automatically configures adapter cards, similar to the Plug and Play standards of modern systems.

Industry Standard Architecture (ISA)

ISA was introduced by IBM and was originally an 8-bit computer bus that was later expanded to z 16-bit bus in 1984. when this bus was originally released it was a proprietary bus, which allowed only IBM to create peripherals and the actual interface. However, in the early 1980’s other manufacturers were creating the bus.

In 1993, Intel and Microsoft introduced a PnP ISA bus that allowed the computer to automatically detect and setup computer ISA peripherals, such as a modem or sound card.

Expansion Card or Add-in Cards

A printed circuit board that plugs into an expansion slot in a computer to provides some extra facility. The sockets normally connect to a bus, and the type of connector and the use to which each contact is put are strictly defined to ensure compatibility between the card and the computer. Cards are available that provides extra memory, communications interfaces, sound I/O capabilities, device interface to extra disks or tape backup devices for instance, or perhaps extra processors in multiprocessor systems.

Expansion Slots

The Expansion Slots allow the computer system to communicate with the outside world. It is used for adding more memory, graphics capabilities, and support for special devices. The boards inserted into the expansion cards.

Expansion slots for PCs come in two basic sizes: half and full size. Half-size slots are also called 8-bit slots because they can transfer 8 bit at a time. Full-size are sometimes called 16-bit slots.

Physical Layer Functions And Services

The physical layer is concerned with the transmission and reception of the unstructured raw bit stream over a physical medium, It describes the electrical/optical, mechanical and functional interfaces to the physical medium, and carries the signals for all of the higher layer.

The major functions and services performed by the Physical Layer are:

1.Establishment and termination of a connection to a communication medium.

2.Participation in the process whereby the communication resources are effectively shared among multiple users. For example, contention resolution and flow control.

3.Modulation, or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel. These are signals operating over the physical cabling (such as copper and optical fibers) or over a radio link.

Synchronous And Asynchronous Operations

Sequential circuits are divided into two main types :-

1.Synchronous

2.Asynchronous

• The send, receive, and reply operations may be synchronous or asynchronous. A synchronous operation blocks a process till the operation completes. An asynchronous operation is non-blocking and only initiates the operation. 

• In the case of synchronous operation, a transfer of data from one point to another is assumed to occur within a fixed time interval known to both the sending and receiving devices. The sender and receiver are synchronized by a signal called the clock, which may be supplied externally to both, or generated by the sender with the data, and occasionally incorporated within it, but often sent on a separate signal line. In the case of asynchronous operation, the sending device or circuit need have no knowledge of the time-scale on which the receiver (and intervening connection) operates, but rather transmits its data with a "data ready" signal and then awaits a reply to the signal sent. Upon receipt of the reply by the sender, it removes its original data and status signal from the line, often (but not necessarily) waiting for the removal of the reply by the sender before proceeding with a second transfer.

Serial And Parallel Models And Bus Characteristics

• A parallel link transmits several streams of data (perhaps representing particular bits of a stream of bytes) along multiple channels (wires, printed circuit tracks, optical fibers, etc.). 
• A serial link transmits a single stream of data. 
• A number of factors allow serial to be clocked at a greater rate:

1. Clock skew between different channels is not an issue (for unlocked asynchronous links).
2. A serial connection requires fewer interconnecting cables (e.g. wires/fibers) and hence occupies less space. The extra space allows for better isolation of the channel from its surroundings. 
3. Crosstalk is less of an issue, because there are fewer conductors in proximity.

Difference ( Comparison) Between Serial And Parallel Bus Characteristics

The Above Slide compares the Parallel and Serial Bus Characteristics.

Comparison Between Serial and Parallel Interfaces

The difference between Serial and Parallel Interfaces are shown in the above image.

Example InterConnect: Star Fabric

Three bridges could be fully interconnected with 2.5Gbps on each link. This could be used to very simply connect racks between Compact PCI chassis in a central office or POP location. In this example, no redesign would be required on existing chassis, boards or software. A front-panel or back-panel module with the Bridge could be inserted into a CPCI slot in each chassis. The chassis could then be interconnected with external shielded twisted pair cables.

To build systems with more than three bus segments a Star would be added. A small Star-based system may look like the illustration above where one Star is interconnected with 6 Bridges. Each bridge supports a full PCI bus bandwidth.

The number and types of configurations are very flexible and can be tuned by the system designer to meet the unique requirements of their application.

In telecom applications, high availability and fault tolerance are extremely important.

With Stars and Bridges, the fabric can be constructed with no single point of failure. In this example topology, a Star is added to the 6 bus segment system shown earlier. This provides redundancy on the links and the Star. If a particular path fails, packets are automatically rerouted in hardware over the remaining good path. An invalid path notification message is sent to the root node so that operations personnel can replace the faulty component.

Multi Layered Protocols

 

Shows architecture is multi layered. Hardware is 3 layers. Real difference is in the transaction layer. This is where fabrics distinguish themselves from each other. Star Fabric and Advanced Switching are similar at the transaction layer. Both Star Fabric and PCI Express can be used in legacy and the other is peer to peer where you pull out P2P driver and put in Star Fabric / Advanced Switching drivers. Which we make available for free.

Serial Interconnect Technology

Serial interconnect technologies has matured to enable high-speed switched architectures with excellent performance and scalability, as well as low pin counts and cost. Clock speeds do jump from 33-133 MHz in the parallel connectivity world, to 2-10 GHz in the serial connectivity world. The new high-speed serial interfaces offer the lowest pin count per connection and maximum performance through a fixed number of connector pins.


Serial InterConnect Features:

• Layered protocol allowing choice of PHY for PCB, cable, or optical 
• Multiple lane configurations, such as 1x, 4x, 8x, and 16x.
• Isochronous capabilities 
• Split-transactions
• Flow control
• Configuration and power management

Different Bus Standards in Computer Networking

Serial interconnects and layered protocols, Parallel models, serial models, Synchronous verses asynchronous operation, Physical layer function and services, logical sub-block, Expansion slots and Add-in cards, Bus evolution and bus wars, ISA, EISA, MCA, PCI, PCI-X, PCIe, PCMIA, Video and monitor types, Ports serial and parallel, USB and Fireware, Ethernet, Mass storage devices, Floppy and hard drives, High and low level formatting, CDs and DVDs, Types, speeds and formatting.

Embedded And Add-in Devices

An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions often with real-time computing constraints. It is usually embedded as part of a complete device including hardware and mechanical parts. It ranges from portable devices such as digital watches and MP4 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants.

Input Output Subsystem

The I/O subsystem connects the system to its peripheral devices using the industry standard 32-bit peripheral component interface (PCI) bus. A fully configured system provides up to eight PCI buses, one for each EPAC. Each bus supports three controllers for a maximum of 24 PCI controllers for the system

Features Of DMA Controllers

The DMAC supports single transfers as well as a block transfer.
             •Single transfer consists of a read burst and a subsequent write burst.
             •A block transfer consists of several successive single transfers.

The data width of a transfer is programmable from 8 bits up to the data bus width in steps of powers to the base of two (8 bits, 16 bits… 1024 bits).

DMA Controllers

Direct memory access (DMA) is a feature of modern computing that allows certain hardware subsystems within the computer to access system memory for reading and/or writing independently of the CPU. Direct Memory Access (DMA) is one of several methods for coordinating the timing of data transfers between an input/output (I/O) device and the core processing unit or memory in a computer. An I/O device often operates at a much slower speed than the core. DMA allows the I/O device to access the memory directly, without using the core. DMA can lead to a significant improvement in performance because data movement is one of the most common operations performed in processing applications.

Interrupt Controller

     An interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution. An interrupt is a line that links the peripheral to the processor. An interrupt is a hardware interrupt when it is requested by one of the PC's hardware components. For example, this is the case when a key is touched and the keyboard wants to get the processor's attention for this event.

     Interrupt-controlled I/O reduces the severity of the two problems mentioned for program-controlled I/O by allowing the I/O device itself to initiate the device service routine in the processor. This is accomplished by having the I/O device generate an interrupt signal which is tested directly by the hardware of the CPU. When the interrupt input to the CPU is found to be active, the CPU itself initiates a subprogram call to somewhere in the memory of the processor; the particular address to which the processor branches on an interrupt depends on the interrupt facilities available in the processor.

Chipsets

A chipsets is a collection of chips or circuits that perform interface and peripheral function for the processor. A chipset s usually designed to work with a specific family of microprocessors. Because it controls communication between the processor and external devices, the chipset plays a crucial role in determining system performance.


FUNCTION OF CHIPSET:

 

The function of chipset can be divided into two major functional groups –

1.Northbridge - The Northbridge subset of a motherboard’s chipset is the set of circuitry or chips that performs one very important function: management of high speed peripheral communication. It is responsible for communication with integrated video using AGP, for instance, and processor to memory communication. It also manage the communication between the Southbridge chipset and the rest of the computer.

2.Southbridge - The Southbridge chipset is responsible for providing support to the myriad onboard peripheral (PS/2, Parallel, IDE, and so on). It is also responsible for managing communication with the other expansion busses, such as PCI, USB and legacy busses.

Motherboard

Motherboard is the central printed circuit board (PCB) in some complex electronic systems, such as modern personal computers. The motherboard is sometimes alternatively known as the main board, system board, or, on Apple computers, the logic board. Motherboard, like a backplane, provides the electrical connections by which the other components of the system communicate, but unlike a backplane, it also hosts the central processing unit, and other subsystems and devices. Motherboards are also used in many other electronics devices such as mobile phones, stop-watches, clocks, and other small electronic devices.



MOTHERBOARD COMPONENTS:

1. Mouse and Keyboard connectors - Keyboard Connectors are two types basically. All PCs have a Key board port connected directly to the motherboard. The oldest, but still quite common type, is a special DIN, and most PCs until recently retained this style connector. The AT-style keyboard connector is quickly disappearing, being replaced by the smaller mini DIN PS/2-style keyboard connector.

2. USB port - USB is the General-purpose connection for PC. A USB connector's distinctive rectangular shape makes it easily recognizable. USB has a number of features that makes it particularly popular on PCs.

3. Parallel port - Most printers use a special connector called a parallel port. Parallel port carries data on more than one wire, as opposed to the serial port, which uses only one wire. Parallel ports use a 25-pin female DB connector. Parallel ports are directly supported by the motherboard through a direct connection or through a dangle.

4. CPU Chip - The central processing unit, also called the microprocessor performs all the calculations that take place inside a pc. Modern CPUs generate a lot of heat and thus require a cooling fan or heat sink. The cooling device (such as a cooling fan) is removable, although some CPU manufactures sell the CPU with a fan permanently attached.

5. RAM slots - Random-Access Memory (RAM) stores programs and data currently being used by the CPU. RAM is measured in units called bytes. RAM has been packaged in many different ways. The most current package is called a 168-pin DIMM (Dual Inline Memory module).

6. Floppy controller - The floppy drive connects to the computer via a 34-pin ribbon cable, which in turn connects to the motherboard. A floppy controller is one that is used to control the floppy drive.

7. IDE controller - Industry standards define two common types of hard drives: EIDE and SCSI. Majority of the PCs use EIDE drives. SCSI drives show up in high end PCs such as network servers or graphical workstations. The EIDE drive connects to the hard drive via a 2-inch-wide, 40-pin ribbon cable, which in turn connects to the motherboard. IDE controller is responsible for controlling the hard drive.

8. PCI slot – PCI stands peripheral component interconnect. The PCI bus is used to connect I/O devices (such as NIC or RAID controllers) to the main logic of the computer. PCI bus has replaced the ISA bus.

9. ISA slot – ISA stands Industry Standard Architecture. It is the standard architecture of the Expansion bus. Motherboard may contain some slots to connect ISA compatible cards.

10. CMOS Battery - To provide CMOS with the power when the computer is turned off all motherboards comes with a battery. These batteries mount on the motherboard in one of three ways: the obsolete external battery, the most common onboard battery, and built-in battery. 

11. AGP slot – In modern motherboard, a single connector that looks like a PCI slot, but is slightly shorter and usually brown. In this slot, inserted a video card. This is an Advanced Graphics Port (AGP) slot.

12. Power supply plug in - The Power supply provides the necessary electrical power to make the pc operate. The power supply takes standard 110-V AC power and converts into +/-12-Volt, +/-5-Volt, and 3.3-Volt DC power. The power supply connector has 20-pins, and the connector can go in only one direction. 26

Assembly, Interpreted and Compiled Software

An assembler consists of little more than a table look up routine, where each word of the source language ( assembly language ) is looked up in a table for its numerical equivalent, which is then output as part of the target language program.

Assembly language generally gives the programmer precise and direct access to every capability of the computer hardware.

An interpreter must read its input program over and over to compute the results, but a compiler translates it only once.

Compilers take longer to get the output from the first time a computer program is run, but subsequent runs are much faster because no additional translation is needed.

CISC Vs RISC Architecture

 

The primary goal of CISC architecture is to complete a task in as few lines of assembly as possible. This is achieved by building processor hardware that is capable of understanding and executing a series of operations. On the other hand, RISC processors only use simple instructions that can be executed within one clock cycle.

Input Output Devices

The term I/O is used to describe any program, operation or device that transfers data to or from a computer and to or form a peripheral device. Every transfer is an output from one device and an input into another. Devices such as keyboards and mouse are input-only devices while devices such as printers are output-only. A writable CD-ROM is both an input and an output device.

Memory Hierarchy

The hierarchical arrangement of storage in current computer architectures is called the memory hierarchy. It is designed to take advantage of memory locality in computer programs. Each level of the hierarchy has the properties of higher bandwidth, smaller size, and lower latency than lower levels.

Storage Devices

A storage device is a hardware device designed to store information. A storage device may hold information, process information, or both. A device that only holds information is a recording medium. Devices that process information (data storage equipment) may either access a separate portable (removable) recording medium or a permanent component to store or retrieve information. The two primary storage technologies are used:-

•Magnetic
•Optical.

Magnetic Storage device :- Magnetic storage uses different patterns of magnetization in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads. There are three types of magnetic storage device:-
•Floppy disks
•Hard disks
•Magnetic tape

Optical Storage device :- An optical disc is an electronic data storage medium that can be written to and read using a low-powered laser beam. The first optical disc, created by James T. Russell in late 1960. A laser read the dots, and the data was converted to an electrical signal, and finally to audio or visual output. Optical disc offers a number of advantages over magnetic storage media. An optical disc holds much more data. The greater control and focus possible with laser beams means that more data can be written into a smaller space. Storage capacity increases with each new generation of optical media. There are three types of optical storage device:-
•Compact Disk Read-Only Memory (CD-ROM)
•Digital Video Disk Read-Only Memory (DVD-ROM)
•CDRW

Memory

Computer memory refers to devices that are used to store data or programs on a temporary or permanent basis for use in an electronic digital computer. Memory is the workspace for the computer’s processor. It is a temporary storage are where the programs and data being operated on by the processor must reside. Memory storage is considered temporary because the data and programs remain there only as long as the computer has electrical power or is not reset. Before being shut down or reset, any data that has been changed should be saved to a more permanent storage device (usually a hard disk) so it can be reloaded into memory in the future.

  
TYPES OF MEMORY:

There are two types of memory –
1.Volatile
2.Non volatile

Volatile memory :- volatile memory is computer memory that requires power to maintain the stored information. Current semiconductor volatile memory technology is usually either static or dynamic RAM. Static RAM exhibits data reminisce, but is still volatile, since all data is lost when memory is not powered. Where as, dynamic RAM allows data to be leaked and disappear automatically without a refreshing. Upcoming volatile memory technologies that hope to replace or compete with SRAM and DRAM include Z-RAM,TTRAM and A-RAM.

Non volatile :- Non volatile memory is computer memory that can retain the stored information even when not powered. Examples of non-volatile memory include read-only memory, flash memory, most types of magnetic computer storage devices (hard disks, floppy disks and magnetic tape), optical discs and early computer storage methods such as paper tape and punch cards.


MAIN MEMORY (RAM)

The main memory of the computer is also known as RAM, standing for Random Access Memory. RAM is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer’s processor. RAM is much faster to read from and write to than the other kinds of storage in a computer. However, the data in RAM stays there only as long as computer is running. When turn computer on again, operating system and other files are once again loaded into RAM. RAM is called “random access” because any storage location can be accessed directly. RAM is organized and controlled in a way that enables data to be stored and retrieved directly to specific locations.



 STATIC, DYNAMIC RAM and CMOS RAM

Static RAM :- In static RAM, a form of flip-flop holds each bit of memory. A static memory cell takes a lot more space on a chip than a dynamic memory cell and it does require a refreshing circuit.

Dynamic RAM :- A dynamic RAM is the most common type of memory in use today. Inside a dynamic RAM chip, each memory cell holds one bit of information and is made up of two parts: a transistor and a capacitor. It requires refreshing circuits.
 
CMOS RAM :- CMOS stands for complementary metal-oxide semiconductor. In PCs, CMOS is more specifically referred to as CMOS RAM. This is a tiny 64-byte region of memory that, thanks to the battery power, retains data when the PC is shut off. The information stored in CMOS is required by a computer´s BIOS.

Central Processing Unit (CPU)

The CPU is capable of executing the instructions that are stored in memory, carrying out arithmetic operations, and performing data transfers. Larger computers have several processors (CPUs). It is responsible for interpreting and executing most of the commands from the computer's hardware and software. It is often called the "brains" of the computer. The main unit inside the computer is the CPU. This unit is responsible for all events inside the computer. It controls all internal and external devices, performs arithmetic and logic operations. The operations a microprocessor performs are called the instruction set of this processor. The instruction set is "hard wired" in the CPU and determines the machine language for the CPU.

Computer And PC Hardware Architectural Components

A PC is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude of software to perform the operator's desired functions. It consists of the following parts :-
                 •Main Memory (RAM)
                 •Processor (CPU)
                 •Auxiliary storage (Disk Drives)

                 •Input and Output devices

Example Of Enterprise Computer Environment

Enterprise Computer is seeking employees willing to provide a truly superior customer service experience for our customers. All employees must have a significantly above average technical proficiency and an ability to answer all technical questions a customer may have in regard to the purchase and setup of computers and high tech equipment. But more importantly, all employees must insure that the customer is fully satisfied with each interaction with Enterprise Computer. In an Industry segment that has a notoriously bad reputation for customer service; Enterprise Computer stands alone in its full commitment to customer satisfaction. For most home users, networking means a dial-up or DSL account. For a growing number of users, however, the network is often an enterprise environment like the one shown in Figure.

Enterprise Computing Environment

In the computer industry, an enterprise is an organization that uses computers. A word was needed that would encompass corporations, small businesses, non-profit institutions, government bodies, and possibly other kinds of organizations.

A multinational company that has interconnected computer users located around the world could be considered an enterprise. The network operating system that they utilize can be referred to as an enterprise operating system. The database that stores their global sales information is both an enterprise application and an enterprise database.

Types Of Computers

Computers are classified in three types:-

1.Based on operational principle
2.Based on capacity, speed and reliability
3.Based on size


1: Based on Operational Principles
 
Analog - Analog computers solve problems by using continuously changing data such as: 1.temperature
2.pressure
3.voltage

Digital - The digital Computers work upon discontinuous or discrete data. They convert the data into digital signal (binary digits 0 and 1) and all operations are carried out on these digits at extremely fast rates.


2. Based on capacity, speed and reliability

Mainframe - Mainframe computers allow many simultaneous users industry, research, and university computing centers typically huge databases, complex mathematical operations, processing millions of transactions everyday.

Minicomputers - Minicomputers mid-range servers supporting smaller number of simultaneous users, typically 50 to 100 larger businesses accounting, billing, and inventory records.

Microcomputers - Microcomputers are personal or desktop computer designed for general use by a single person home and all types of businesses entertainment, communication, personal databases, and spreadsheets, word processing, accounting, inventory control, research.


 3. Based On Size:

Desktop - A Personal Computer that is not designed for portability. The computer is set up in a permanent location. Most desktops offer more power, storage and versatility for less cost.

Laptop - These are also called notebooks. Laptops are portable computers that integrate the display, keyboard, a pointing device or trackball, processor, memory and hard drive all in a battery-operated package slightly larger than an average hardcover book.

Palmtop - More commonly known as Personal Digital Assistants (PDAs). Palmtops are tightly integrated computers that often use flash memory instead of a hard drive for storage. These computers usually do not have keyboards but rely on touch screen technology for user input. Palmtops are typically smaller than a paperback novel, very lightweight with a reasonable battery life. A slightly larger and heavier version of the palmtop is the handheld computer.

Workstation - A desktop computer that has a more powerful processor, additional memory and enhanced capabilities for performing a special group of task, such as 3D Graphics or game development.

Server - A computer that has been optimized to provide services to other computers over a network. Servers usually have powerful processors, lots of memory and large hard drives.

Supercomputer- This type of computer usually costs hundreds of thousands or even millions of dollars. Although some supercomputers are single computer systems, most are comprised of multiple high performance computers working in parallel as a single system. The best known supercomputers are built by Cray Supercomputers.

Wearable- The latest trend in computing is wearable computers. Common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cell phones, even clothing.

How Computer Operates or Start Ups or Works

The program and the necessary data are entered into the computer system from an input device, and are stored in main memory where they can be accessed as needed.

Now, the CPU retrieves the instructions from the main memory, one by one, and decodes each instruction to determine what operation to be performed.

When required by instruction, the CPU also retrieves the necessary data from main memory.

The CPU then performs the operation required by the instruction, which might be arithmetic or logical operation. As each instruction is performed, the results are either temporarily saved by the CPU or are stored in main memory.

The processing cycle (retrieve instruction, decode and execute instruction, save results) is repeated until all the program instructions have been carried out by the CPU. The final results are then either stored in main memory, or are sent to an output device such as a printer.








Related Keywords:
       How Computer Works
       How Computer Boots
       Boot Startup of Computer
       How PCs Work?

Computer Components

Input:- To perform computation Computer requires input of data from users. The data is entered using an input device, such as a keyboard or mouse.

Central Processing Unit: The Computer processes the data according to a set of instructions called program. It is responsible for interpreting and executing most of the commands from the computer’s hardware and software. It s often called the “brain” of the computer.

Output:-  The Computer returns the processed information in a form that can be used by the user. The information is printed, displayed, or reported using some type of output device like printer or monitor.

Memory:-  Memory is the workspace for the computer’s processor. The computer saves the data or instruction for future retrieval is called memory.

What is a computer

Computer derives its name from the word Compute that means calculation. A computer is an electronic device that processes or transforms data into useful information by executing a series of predefined instructions. In today, a computer is not only limited to computation, but also used for making phone calls, maintaining databases, listening songs, viewing movies etc. There are two principal characteristics of a computer – 1.It responds to a specific set of instructions in a well-defined manner. 2.It can execute a prerecorded list of instructions.

Overview of PC Architecture

      What is a computer, How computers operate, Types of computers, The computing environment, The enterprise computer environment, Types of computers in the enterprise, Where the PC fits in the enterprise environment, Computers and PC hardware architectural components, CPUs, Chipsets, Memory, I/O, Component interaction, PC software, CISC verses RISC computer models, Software, Assembly, Interpreted and compile software, Mother board components, CPU, Chipsets, Interrupt and DMA controllers and how they work, Memory, static and dynamic RAM and their derivations BIOS, CMOS RAM, I/O subsystem, Embedded and add-in devices.