Types of Computers

Main Frames Computers

These types of computers Large, Powerful and Expensive computers used in large organizations. Now main frame computers play a central role of daily operations. Main frames ply main role of E-Business environment. These types of computers are mainly use for bulk data processing, consumer statistics and process control. Mainly used in Tele Communication, Airline Reservation Systems, Banking and etc. Capable of handling hundreds or even thousands of uses simultaiously. Each user access the mainframe via a terminal. Most main frames are designed to handle only a specific set of tasks. The major advantage of main frame computer is large data capacity; long time satiable, at a time can run more than one operating system, multiple servers, and high speed calculation. At the same time these types of computers have disadvantages like high capital cost, high initial installation cost, significantly compare to PC high maintenance cost, low security and its occupied large space are those disadvantages.

Hard Drive Interfaces

The hard disk cannot communicate directly with the CPU or itself. For the hard disk to communicate with the computer, it depends on two more components.  

                                                           

The Controller, which links the drive to the computer

 Host Bus adapter, which converts the signals used by the hard drive to those used and understood by the computer.

ST-506

The ST-506 was the original IBM PC interface. There have two cables, the both cables were used to connect the hard disk to separate controller.

A 20-pin data cable and 34-pin data control cable. The data was transferred on the cable via a serial format one bit at a time. This interface supports the MFM, RLL and ARLL encoding mode of procedure.

Components of PC

A modern PC is both simple and complicated. It is simple in the sense that over the years, many of the components used to conduct a system have become integrated with other components into fewer actual parts. It is complicated in the sense that is part in a modern system performs many more functions than it did the same type of parts on older systems. The typical components and peripherals found in basic PC system as follows.