The Computer System. Components of a computer. Strengths of Computers. Basic Components. Other Components

Transcription

1 The Computer System Components of a computer Basic Components Input Devices System Output Devices Storage Devices Other Components Peripheral Devices Communication Devices 1 2 Strengths of Computers Speed Reliability Accuracy 3 4

2 Data Representation Bits off or on digital value, short term for binary digits. Bytes a group of eight bits, a unique code can be assigned to 256 different data possibilities. (e.g represents the letter A.) Coding Scheme ASCII (American Standard Code for Information Interchange) 8 bits; used in many PC & minicomputer. EBCDIC (Extended Binary Coded Decimal Interchange Code) 8 bits; used in Mainframe Computer Character ASCII EBCDIC Character ASCII EBCDIC A B C D Unicode 16 bits can represent > characters 6 1. System Motherboard A circuit board that contains most of the electronic components of the system unit. Expansion Slots (for display card, modem card ) Ports & Connectors BIOS Chip Slot 7 DIMM Sockets for 8

3 Components of System Motherboard Central Processing () Upgrade sockets es Expansion Slot Ports & connectors It is the brain of a computer system The : receives input. interprets instructions provided by programs. directs other components of the system to act. processes data. controls output It coordinates the flow of data and instructions. It contains a clock that generates a uniform stream of electrical pulses that synchronize the operating of the and other computer components Arithmetic and Logic () It performs calculations and comparisons of data

4 They hold program instructions, data values, and memory locations as the computer executes a program. 13 es They are electrical pathways that carry signal (bits) between a s components and outside devices. 14 Multiprocessing Large computer systems, as well as newer workstations and network servers, frequently contain more than one central processing unit. Multiple s enable the computer to execute more than one instruction or process more than one program, at the same time. 15 Main Before programs are executed or data processed, they must first enter into main memory. Main memory holds information read from disk or captured by input devices. The than moves information from the main memory into its registers for processing. RAM ROM CACHE 16

5 Random Access (RAM) Integrated circuit containing data that can be read and written by the microprocessor or other devices. Volatile - programs & data stored in RAM are erased when the power is off. Read Only (ROM) Chips that store information or instructions that can be read and used, but cannot be changed. Non-volatile - retains its contents even the power is turned off. The instructions to start the computer are on a special chip known as a ROM BIOS chip (Basic Input/Output System) Cache Cache memory is a specialized chip used with the computer's memory. Cache chips are faster and more expensive than regular RAM chips. The computer stores the most frequently used instructions and data in cache. Cache has a relatively small storage capacity but can significantly In summary, memory accepts and holds program instruction and data acts as the s source for data and instructions and as a destination for operation results holds the final processed information until it can be sent to the desired output or storage devices, such as printer or increase the system's speed. disk drive 19 20