The Components of the System Unit

1. Chapter 4 The Components of The System Unit Matt Vanacore, Ryan Bratton, Thomas Bender

2. The System Unit • Is a case that contains electronic components of the computer used to process data • The motherboard is the main circuit board of the system unit • A chip is a small piece of semi conducting material on which integrated circuits are etched

3. Processor • Interprets and carries out the basic instructions that operate a computer • Contains a control unit and a arithmetic logic unit (ALU) • Performs arithmetic operations, which is basic arithmetic (addition, subtraction etc) and Comparison, which involves comparing data with other data. • Logical operations uses “and,” “or,” and “not.” It must verify conditions. • The control unit directs and coordinates most of the operations in the computer. • Both of these units work together to perform processing operations

4. Processor Cont. • Registers are small high speed storage locations that temporarily hold data. • The computer relies on the System Clock to control timing of all computer operations. • Each tick is a clock cycle, clock speed is measured by the number of ticks per second. • A hertz is one cycle per second

5. Processor Cont. • The four major manufacturers of Processors are Intel, IBM, AMD, and Motorola. • Most high performance computers use the Pentium Processor, which is manufactured by Intel. • AMD manufactures processors similar and compatible to Intel, but not always as powerful

6. Data Representation • Two types of data representation • Analog is a continuous signal that varies in strength and quality • Humans • Digital recognize only two discrete states, on and off • Computers • Binary system (bit) is a number system that has two unique digits, 0 and 1. This is the smallest unit of data • 8 bites together form a byte, and this has enough combinations to represent 256 individual characters

7. Memory • Consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processed data. • Three basic categories: • Operating system and other system software that control or maintain the computer and its devices • Application programs that carry out specific tasks • Word • Data being processed by the application programs and resulting information. • RAM consists of memory chips that can be read from and written to by the processor and other devices

8. Memory Continued • RAM has three different types • Dynamic RAM are chips that must be re-energized constantly or they lose their contents • Static RAM chips are faster and more reliable then any variation of DRAM chips • Magnetoresistive Ram stores data using magnetic charges instead of electrical charges

9. Memory Cont. • Memory Cache helps speed the process of the computer because it stores frequently used instructions and data. • L1 cache is built directly into the processor. • L2 cache is slightly slower than L1, but has much larger capacity. • L3 cache is a cache separate from the processor chip on the motherboard.

10. Memory Cont. • ROM refers to every chip storing permanent data and instructions. • Firewall contains permanently written data, instructions, or information. • A PROM chip is a blank ROM chip onto which a programmer can write permanently. • EEProm chip allows a programmer to erase the microcode with an electrical signal. • FLASH MEMORY is a type of none volatile memory that can be erased electronically and re-written.

11. Memory Cont. • CMOS complimentary metal-oxide semiconductor technology because it provides high speeds and consumes little power. • Memory Access Time is the amount of time it takes the processor to read data, instructions, and information from memory. • Nanosecond is one billionth of a second

12. Expansion Slots and Adapter Cards • Expansion slide is a socket on the motherboard that can hold an adapter card. • An adapter card is a circuit board that enhances functions of a component. • A peripheral is a device that connects to the system unit and is controlled by the processor in the computer. • A sound card enhances the sound generating capabilities of a personal computer by allowing sound to be input through microphone and output through external speakers. • A video card converts computer output into a signal that travels through a cable to the monitor which displays an image on the screen.

13. ADAPTER CARDS CONTINUED • A modem card is a communication device that enables computers to communicate via telephone lines, television or other media. • A network card is a communications device that allows a computer to access a network. • Plug and play is the computer automatically configuring adaptor cards. • The pc card slot hold the pc card and the pc card is a small device that adds memory, storage, sound, and other communications. • Flash memory card is used to transfer data from mobile devices to desk top computers.

14. Ports and Connectors • A port is a point at which a peripheral attaches to a system unit to send or receive data • A connector joins a cable to a peripheral • Male connectors have one or more exposed pins • Female connectors have matching holes to accept the pins on a male connector • A gender changer is a device that connects both male and male or female and female • Serial port is a type of interface that connects a device to a system unit by transmitting data one bit at a time • A parallel port is a interface that connects devices by transferring more then one bit at a time.

15. Ports and Connectors Continued • USB ports can connect up to 127 different peripherals together with a single connector type • A USB hub is a device that plugs into a USB port on the system unit and contains multiple USB ports • Firewire port is similar to a USB, but it transfers data faster • MIDI port is the electronic music industries that defines how devices such as sound cards represent sound electronically • SCSI port is a high speed parallel port that allows you to attach SCSI peripherals such as disc drives and printers • IrDA transmits signals to a computer via infrared light waves • Bluetooth ports uses radio waves to transmit data

16. Buses • A bus allows the various devices both inside and attached to the system unit to communicate • Word size is the number of bits the processor can interpret and execute at a given time • Data transmitted to memory travels from expansion bus via the expansion bus and the system bus.

17. Bays • A bay is an opening inside the system unit • In which you can install additional equipment. • Rectangular openings called Drive bays typically hold disk drives. • An external drive bay allows the user to access the drive from outside the system unit.

18. Power Supply • Power Supply is the component of the system unit that converts the wall outlet AC power into DC power. • An AC Adapter is an external power supply, which modems, speakers, and tape drives get their power from.

19. Mobile Computers and Devices • Two types of computing mobile devices are the tablet PC (Laptop) and a PDA (Palm Pilot). • The laptop is similar to the desktop in almost every way except that many of the devices are part of the system unit. • PDA’s have external keyboards and they often have Bluetooth ports so they can communicate wirelessly.

20. Putting It All Together • People buying computers should how the components of the system work because they influence many aspects of the computer.