HARD DISK...

A hard disk drive (HDD) is a non-volatile, random access device for digital data. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the platters.
Introduced by IBM in 1956, hard disk drives have fallen in cost and physical size over the years while dramatically increasing in capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s.They have maintained this position because advances in their areal recording density have kept pace with the requirements for secondary storage.Today's HDDs operate on high-speed serial interfaces; i.e., serial ATA (SATA) or serial attached SCSI (SAS).

AN INTERNAL STRUCTURE OF MOTHER BOARD

In personal computers, a motherboard is the central printed circuit board (PCB) in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple computers, the logic board.It is also sometimes casually shortened to mobo.
Prior to the advent of the microprocessor, a computer was usually built in a card-cage case or mainframe with components connected by a backplane consisting of a set of slots themselves connected with wires; in very old designs the wires were discrete connections between card connector pins, but printed circuit boards soon became the standard practice. The Central Processing Unit, memory and peripherals were housed on individual printed circuit boards which plugged into the backplane.
During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard (see below). In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. As of the late 1990s, many personal computer motherboards supported a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-end systems for 3D gaming and computer graphics typically retained only the graphics card as a separate component.
The early pioneers of motherboard manufacturing were Micronics, Mylex, AMI, DTK, Hauppauge, Orchid Technology, Elitegroup, DFI, and a number of Taiwan-based manufacturers.
The most popular computers such as the Apple II and IBM PC had published schematic diagrams and other documentation which permitted rapid reverse-engineering and third-party replacement motherboards. Usually intended for building new computers compatible with the exemplars, many motherboards offered additional performance or other features and were used to upgrade the manufacturer's original equipment
The term mainboard is applied to devices with a single board and no additional expansions or capability. In modern terms this would include embedded systems and controlling boards in televisions, washing machines, etc. A motherboard specifically refers to a printed circuit board with expansion capability.

A COMPLETE COMPUTER SYSTEM..

mainly the computer system consists of monitor,cpu,keyboard,mouse,speakers....

this is the basic components of a complete computer system....

the computer system an electrical device which is used to multiple purposes, in technical fields,

this vast technology is increasing rapidly and demanding in upcoming generation....

all types of information is shared or available for human beings with the help of this machine

INTERNAL STRUCTURE OF C.P.U

Processor Organization


  

To understand the organization of the CPU, let us consider the requirements placed on the CPU, the things that it must do:

  

    * Fetch instruction: The CPU reads an instruction from memory.
    * Interpret instruction: The instruction is decoded to determine what action is required.
    * Fetch data: The execution of an instruction may require reading data from memory or an I/O module.
    * Process data: The execution of an instruction may require performing some arithmetic or logical operation on data.
    * Write data: The results of an execution may require writing data to memory or an I/O module.


  

To do these things, it should be clear that the CPU needs to store some data temporarily. It must remember the location of the last instruction so that it can know where to get the next instruction. It needs to store instructions and data temporar­ily while an instruction is being executed. In other words, the CPU needs a small internal memory.

  

Figure 1 is a simplified view of a CPU, indicating its connection to the rest of the system via the system bus. You will recall (Lecture 1) that the major components of the CPU are an arithmetic and logic unit (ALU) and a control unit (CU). The ALU does the actual computation or processing of data. The con­trol unit controls the movement of data and instructions into and out of the CPU and controls the operation of the ALU. In addition, the figure shows a minimal internal memory, consisting of a set of storage locations, called registers.