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

Copyright 2004 The System Unit Is a case that contains electronic components of the computer used to process data 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 A chip is a small piece of semi conducting material on which integrated circuits are etched

Copyright 2004 Processor Interprets and carries out the basic instructions that operate a computer Interprets and carries out the basic instructions that operate a computer Contains a control unit and a arithmetic logic unit (ALU) 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. The control unit directs and coordinates most of the operations in the computer. Both of these units work together to perform processing operations Both of these units work together to perform processing operations

Copyright 2004 Processor Cont. Registers are small high speed storage locations that temporarily hold data. 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. 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

Copyright 2004 Processor Cont. The four major manufacturers of Processors are Intel, IBM, AMD, and Motorola. 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. 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 AMD manufactures processors similar and compatible to Intel, but not always as powerful

Copyright 2004 Data Representation Two types of data representation Two types of data representation –Analog is a continuous signal that varies in strength and quality Humans Humans –Digital recognize only two discrete states, on and off Computers Computers Binary system (bit) is a number system that has two unique digits, 0 and 1. This is the smallest unit of data 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 8 bites together form a byte, and this has enough combinations to represent 256 individual characters

Copyright 2004 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. 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: 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 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 RAM consists of memory chips that can be read from and written to by the processor and other devices

Copyright 2004 Memory Continued RAM has three different types 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

Copyright 2004 Memory Cont. Memory Cache helps speed the process of the computer because it stores frequently used instructions and data. 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.

Copyright 2004 Memory Cont. ROM refers to every chip storing permanent data and instructions. ROM refers to every chip storing permanent data and instructions. Firewall contains permanently written data, instructions, or information. Firewall contains permanently written data, instructions, or information. A PROM chip is a blank ROM chip onto which a programmer can write permanently. 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. 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. FLASH MEMORY is a type of none volatile memory that can be erased electronically and re-written.

Copyright 2004 Memory Cont. CMOS complimentary metal-oxide semiconductor technology because it provides high speeds and consumes little power. 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. 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

Copyright 2004 Expansion Slots and Adapter Cards Expansion slide is a socket on the motherboard that can hold an adapter card. 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. 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 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 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. A video card converts computer output into a signal that travels through a cable to the monitor which displays an image on the screen.

Copyright 2004 ADAPTER CARDS CONTINUED A modem card is a communication device that enables computers to communicate via telephone lines, television or other media. 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. 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. 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. 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. Flash memory card is used to transfer data from mobile devices to desk top computers.

Copyright 2004 Ports and Connectors A port is a point at which a peripheral attaches to a system unit to send or receive data 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 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 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. A parallel port is a interface that connects devices by transferring more then one bit at a time.

Copyright 2004 Ports and Connectors Continued USB ports can connect up to 127 different peripherals together with a single connector type 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 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 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 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 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 IrDA transmits signals to a computer via infrared light waves Bluetooth ports uses radio waves to transmit data Bluetooth ports uses radio waves to transmit data

Copyright 2004 Buses A bus allows the various devices both inside and attached to the system unit to communicate 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 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. Data transmitted to memory travels from expansion bus via the expansion bus and the system bus.

Copyright 2004 Bays A bay is an opening inside the system unit A bay is an opening inside the system unit In which you can install additional equipment. In which you can install additional equipment. Rectangular openings called Drive bays typically hold disk drives. 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. An external drive bay allows the user to access the drive from outside the system unit.

Copyright 2004 Power Supply Power Supply is the component of the system unit that converts the wall outlet AC power into DC power. 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. An AC Adapter is an external power supply, which modems, speakers, and tape drives get their power from.

Copyright 2004 Mobile Computers and Devices Two types of computing mobile devices are the tablet PC (Laptop) and a PDA (Palm Pilot). 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. 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. PDA’s have external keyboards and they often have Bluetooth ports so they can communicate wirelessly.

Copyright 2004 Putting It All Together People buying computers should how the components of the system work because they influence many aspects of the computer. People buying computers should how the components of the system work because they influence many aspects of the computer.