3Computer Components What does all this jargon mean? Intel Pentium 4 Processor at 3.20 GHz512 MB Dual Channel shared SDRAM at 400 MHz80 Ultra ATA/100 Hard Drive17" flat-panel Display8X DVD + R/+RW Drive with CD-RWAltec Lansing Surround Sound SpeakersIntegrated 5.1 Audio with Dolby DigitalWordPerfect and America OnlineBe patient!If you don'tknow now, youshould knowshortly
4Sizes in Perspective Intel Processor speed 3.20 GHz (3,200,000,000 cycles per second)SDRAM (Synchronized Dynamic RAM)size 512 MB (512X220)speed 400 MHz (400,000,000 cycles/sec)Ultra ATA-10080 GB (80X230)Transfer rate 100MB per secondFlat 17” screen dot pitch .28 (distance between the dots)To which do theseapply?Bigger is betterFaster is betterSmaller is better
5Sizes in Perspective DVD-ROM (Digital Versatile Disk ROM) 8X is how fast data can be accessed on the driveR/RW (Record and Read/Write)
7Sizes in Perspective A coil of wire nearly 1,000 feet long Distance traveled by an electron along the wire in the space of a microsecondA short piece of wireIn the space of a nanosecondA bag containing grains of pepperIn the space of a picosecond
8Stored-Program Concept Figure 5.1 The von Neumann architecture
9Memory Memory A collection of cells, each with a unique physical address;bothaddresses andcontents are inbinaryWhat is this????Integer? Instruction? Part of image?We don’t know! It is just a bit pattern
10Arithmetic/Logic Unit Performs basic arithmetic operations such as addingPerforms logical operations such as AND, OR, and NOTMost modern ALUs have a small amount of special storage units called registerse.g. One* (Two+Three). Two is added to Three and then is multiplied to One. The result of the addition is stored in a register and then multiplied by One. Access to Registers is faster than access to memory locations.
11Input/Output Units Input Unit A device through which data and programs fromthe outside world are entered into the computer;Can you name three?Output unitA device through which results stored in thecomputer memory are made available to theoutside world
12Control Unit Control unit The organizing force in the computer – includes 2 registers:Instruction register (IR)Contains the instruction that is being executedProgram counter (PC)Contains the address of the next instruction to beexecutedCentral Processing Unit (CPU)ALU and the control unit (CU)
13Flow of Information Bus A set of wires that connect all major sections Figure 5.2 Data flow through a von Neumann architectureMotherboardThe main circuit board of a personal computer
14The Fetch-Execute Cycle All the instructions are about storing, retrieving, and processing data.Fetch the next instruction – Retrieves the address stored in the Program Counter and stores it at the Instruction Register (IR). The program counter is incremented to point to the next address from which the new instruction is to be fetchedDecode the instruction – e.g. access data from an input device or send data to an output device, etc. Computer can execute only instructions that are expressed in machine language-literally build into the circuits.Get data if needed – e.g. add the contents of a memory location to a register, the control unit must get the contents of the memory location.Execute the instruction - executes the instruction that was fetched and decoded.Why is it called a cycle?
15The Fetch-Execute Cycle Figure 5.3 The Fetch-Execute Cycle
16RAM and ROM Random Access Memory (RAM) Memory in which each location can be accessed and changedRead Only Memory (ROM)Memory in which each location can be accessed but not changedRAM is volatile, ROM is notWhat does volatile mean?
17Secondary Storage Devices Why is it necessary to have secondary storage devices?Can you name some of these devices?
18Magnetic TapeThe first truly mass auxiliary storage device was the magnetic tape driveTape drives have amajor problem; canyou describe it?Figure 5.4 A magnetic tape
19Magnetic DisksFigure 5.5 The organization of a magnetic disk
20Magnetic Disks History Floppy disks (Why "floppy"?) " in diameter "late 1970, 5 1/2"now, 3 1/2"
21Magnetic DisksWhen the Read/Write Head is over the proper track to access the proper block. Four measures of a disk drive’s efficiency:Seek timeTime it takes for read/write head to be over right trackLatencyTime it takes for sector to be in positionAccess timeTime it takes for a block to start being read; the sum of Seek time and LatencyTransfer timeThe rate at which data moves from the disk to memory
22Compact DisksCDA compact disk that uses a laser to read information stored optically on a plastic disk; data is evenly distributed around trackCD-ROM read-only memoryCD-DA digital audioCD-WORM write once, read manyRW or RAM both read from and written toDVDDigital Versatile Disk, used for storing audio and video
23Touch Screens Touch screen A computer monitor that can respond to the user touching the screen with a stylus or fingerThere are four typesResistiveCapacitiveInfraredSurface acoustic wave (SAW)
25Touch Screens Resistive touch screen A screen made up of two layers of electrically conductive materialOne layer has vertical lines, the other has horizontal linesWhen the top layer is pressed, it comes in contact with the second layer which allows electrical current to flowThe specific vertical and horizontal lines that make contact dictate the location on the screen that was touched
26Touch Screens Capacitive touch screen A screen made up of a laminate applied over a glass screenLaminate conducts electricity in all directions; a very small current is applied equally on the four cornersWhen the screen is touched, current flows to the finger or stylusThe location of the touch on the screen is determined by comparing how strong the flow of electricity is from each corner
27Touch Screens Infrared touch screen A screen with crisscrossing horizontal and vertical beams of infrared lightSensors on opposite sides of the screen detect the beamsWhen the user breaks the beams by touching the screen, the location of the break can be determined
28Touch Screens Surface acoustic wave (SAW) A screen with crisscrossing high frequency sound waves across the horizontal and vertical axesWhen a finger touches the surface, corresponding sensors detect the interruption and determine location of the touch
29Non-von Newmann Architectures: Synchronous processing One approach to parallelism is to have multiple processors apply the same program to multiple data setsFigure 5.7 Processors in a synchronous computing environment
30Non-von Newmann Architectures: Pipelining Arranges processors in tandem, where each processor contributes one part to an overall computationFigure 5.8 Processors in a pipeline
31Non-von Newmann Architectures: Independent Processing with Shared Memory Different processors doing different things with different data.Processors communicate through shared memory.Figure 5.9 Shared memory configuration of processors