The System Unit Components

1. Chapter 4 The Components of the system unit Created By: N.AlJaffan Modified By:S.Abudawood

2. The Components of the system unit Chapter 4 System Unit is a case that contains electronic components of the computer used to process data. • Made of metal or plastic to protects the internal components from damage. • All computers have a system unit. It is available in variety of shapes & sizes.

3. System unit Handheld controller The Components of the system unit Chapter 4 System unit System unit System unit System unit

4. The Components of the system unit Chapter 4 6 7 1 2 5 3 motherboard 4 4 4 4

5. The Components of the system unit Chapter 4 • Processor interprets & carries out the basic instructions that operate a computer. • Memory holds data waiting to be processed & instruction waiting to be executed. • Processor & Memory are connected to a circuit board called the motherboard. • Adapter cards (expansion slots): are circuit boards that provide connections and functions not built into the motherboard. • Devices outside the system unit often attach to the ports. • A drive bay holds one or more disk drive. • The Power supply provide the computer with the electricity.

6. The Components of the system unit Chapter 4 Motherboard , called system board. • It is a main circuit board of the system unit. • Many electronic components attach to the motherboard, others are built into it. Ex: adapter cards, a processor chip and a memory module. http://www.howstuffworks.com/microprocessor.htm

7. CPU Arithmetic/Logic Unit (ALU) Control Unit Central Processing Unit (CPU) Chapter 4 Processor,called the central processing unit (CPU), Microprocessor. • Its contain a control unit & an arithmetic logic unit (ALU). • These 2 components work together to perform processing operations.

8. Chapter 4 information Storage Devices

9. Central Processing Unit (CPU) Chapter 4 The operations typically performed by a CPU are: • CPUs control the reading of programs and input files. • CPUs process data according to instructions in a program. • CPUs control the creation of output.

10. The Components of the system unit Chapter 4 The Arithmetic Logic Unit performs arithmetic, comparison and other operations. The Control Unit • Handles the transmission of data into and out of the CPU and supervises its overall operations.

11. Central Processing Unit (CPU) Chapter 2 Registers The CPU contain special storage areas called registers. Their function is to hold instructions, data values, memory addresses of both the instructions and data. There are 4 basic types of it: • Instruction register hold instruction • Address register hold address of( data , next instruction ). • Storage register store data retrieved from main memory prior to processing. • Accumulator store the results of arithmetic & logic operations

12. Central Processing Unit (CPU) Chapter 4 The System Clock • Every CPU has a clock, It’s a small quartz crystal circuit , which generates regular clock pulses that control the timing of all computer operations. • Processing actions occur at each “tick” of the electronic clock. • The Speed of the clock determines the speed at which the CPU can process data. • Speed is measured in megahertz (MHz) or (GHz).

13. Central Processing Unit (CPU) Chapter 4 Comparison of Personal computer Processors The leading processor chip manufacturers for personal computers are • Intel (used in PCs) • AMD ( advanced Micro Devices) (used in PCs) • Motorola ( used in Apple) • Alpha (used in workstations and high-end servers)

14. 8-bit byte for the number 3 Binary Digit (bit) Electronic Charge Electronic State Central Processing Unit (CPU) Chapter 4 How the CPU represents data • Binary system based on two digits 0 and 1. 0 : off 1 : on • Bit is a the smallest unit of data the computer can process. • Byte a group of 8 bits. • A byte can be represent characters. • Characters can be a letter, digit, or symbol.

15. Central Processing Unit (CPU) Chapter 4 How the CPU represents data The different combinations of 0s and 1s are defined by patterns called a coding schema. There are tow popular coding scheme: • ASCII stands for American Standard Code for Information Interchange. • EBCDIC stand for Extended Binary Coded Decimal Interchange Code.

16. 8-bit byte for the number 3 8-bit byte for the number 5 8-bit byte for the capital letter T Data Representation

17. Memory Chapter 4 Memory • Memory consist of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processed data ( information). • Memory usually consist of one or more chips on the motherboard.

18. Memory Chapter 4 Memory Stores 3 basic categories of items: • The operations • Application programs • The data being processed by the application programs and resulting information.

19. Memory Chapter 4 Memory sizes It’s the number of bytes the chip or devices has available for storage.

20. Type of Memory Chapter 2 Type of Memory The system unit contains tow types of memory: • Volatile memory - • Loses its contents . • Temporary memory. • Example, RAM. • Nonvolatile memory- • doesn't lose its content when power is removed form the computer. • Permanent memory. • Example, ROM, Flash memory, and CMOS.

21. RAM (Main Memory) Chapter 4 RAM ( Random Access Memory ), Also Called main memory. • consists of memory chips that can be read from and written to by the processor and other devices. • The content my changed. Saving is a process of copying items from RAM to a storage device such as a hard disk.

22. RAM Chapter 4 RAM ( Random Access Memory ) • RAM chips usually reside on a memory module, which is a small circuit board. • Memory slots on the motherboard hold memory modules.

23. ROM Chapter 4 ROM ( Read Only Memory) • The data on most ROM chips cannot be modified. • Manufacture of ROM chips often record data, instructions, or information on the chip when they manufacture the chip. • Computers almost always contain a small amount of read-only memory that holds instructions for starting up the computer.

24. Types of ROM Chapter 4 Types of ROM: • PROM(programmable read-only memory): A PROM is a memory chip on which you can store a program. But once the PROM has been used, you cannot wipe it clean and use it to store something else. Like ROMs, PROMs are non-volatile. • EPROM(erasable programmable read-only memory): An EPROM is a special type of PROM that can be erased by exposing it to ultraviolet light. • EEPROM(electrically erasable programmable read-only memory): An EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge.

25. Memory Access Time Chapter 4 Memory Access Time • It is the amount of time takes the processor to read data, instructions, information from memory. • It’s affects how fast the computer process data. • Access time on memory can be more than 200,000 times faster than accessing data on a hard disk because the mechanical motion of it.

26. Memory Access Time Units Chapter 4 Memory Access Time

27. Expansion Slot and Adapter Cards Chapter 4 Expansion Slot and Adapter Cards • Expansion slotis a socket on the motherboard that can hold an adapter card • Adapter card sometimes called an expansion card • is a circuit board that enhances functions of a component of the system unit and/or provides connections to peripherals. • Peripheralis a device that connects to a system unit and is controlled by the processor. Ex: keyboard, printer.

28. Expansion Slot and Adapter Cards Chapter 4 Types of adapter cards

29. Ports and Connectors Chapter 4 Ports and Connectors Port is the point at which aperipheral attaches to or communicates with a system unit so the peripheral can send data to or receive information from the computer. • the term jack sometimes is used to identify audio and video ports. • Port have a different types of connectors, A connectors joins a cable to a peripheral.

30. Ports and Connectors Chapter 4 Serial Ports is a type of interface that connects a device to the system unit by transmitting data one bit at a time.

31. Ports and Connectors Chapter 4 Parallel Ports is an interface that connects a device by transferring more than one bit at a time. • The printers using a parallel port.

32. Chapter 4

33. Ports and Connectors Chapter 4 USB Ports, Short for universal serial bus port. • Can connect up to 127 different peripherals together with a single connector. • USB hub is a device that plugs in a USB port on the system & contains multiple USB ports.

34. Ports and Connectors Chapter 4 FireWire Ports Previously called an IEEE 1394 port. • It is similar to a USB port in that it can connect multiple type of device that require faster data transmission speeds to a single connector, such as digital video camera, color printers, scanners, .. etc. • Allow you to connect up to 63 devices together. • You can use a FireWire hub to attach multiple devices to a single FireWire port. • USB and FireWire are replacing all other types of port.

35. Ports and Connectors Chapter 4 Special-Purpose Ports These ports are not included in typical computers. • MIDI Port • SCSI Port • IrDA Port • Bluetooth Port

36. Ports and Connectors Chapter 4 MIDI Port, short for musical instrument digital interface. • Serial port • Connect the system unit to keyboard. SCSI Port • A special high-speed parallel port. • Allow you to attach SCSI peripherals such as disk driver and printers.

37. Ports and Connectors Chapter 4

38. Ports and Connectors Chapter 4 BUSES a set of electronic signal pathways that allows information and signals to travel between components inside or outside of a computer. Buses transfer bits • from input devices to memory. • from the processor to memory, and from memory to the processor. • from memory to output devices.

39. Power Supply Chapter 4 Power Supply Is a component of the system unit that supply computer with power.