Digital Electronics and File ManagementDigital Data RepresentationSlide 3Coding SystemsSlide 5Quantifying Bytes and BitsMicroprocessor (Processor)MotherboardInside a typical desktop computerSlide 10Slide 11Microprocessor ComponentsMicroprocessor PerformanceMemory TypesRAMSlide 16Virtual MemoryROMCMOSComputer File CharacteristicsFile-naming conventionsFile LocationsFilesSlide 24Slide 25Using FilesSlide 27Digital Electronics Digital Electronics and File Managementand File ManagementUnit DUnit DDigital Data Representation Digital Data Representation The form in which The form in which information is conceived, information is conceived, manipulated and recorded on manipulated and recorded on a digital device.a digital device.Uses discrete Uses discrete digits/electronic signalsdigits/electronic signals-1,0 (bits - binary digits)1,0 (bits - binary digits)-On/Off On/Off -Yes/NoYes/No-Byte = 8 bits = 1 character Byte = 8 bits = 1 characterDigital Data Representation Digital Data RepresentationCoding Systems Coding Systems Depends on computer Depends on computer ASCIIASCII (7 bits) (7 bits) Extended ASCIIExtended ASCII (8 bits - (8 bits - current PCs)current PCs)EBCIDICEBCIDIC (8 bits - older (8 bits - older IBM machines )IBM machines )UnicodeUnicode (16 bits - good (16 bits - good for languages - future)for languages - future)Coding Systems Coding SystemsQuantifying Bytes and BitsQuantifying Bytes and BitsBit = b Bit = b Nibble = Half of a byteNibble = Half of a byteByte = B Byte = B Kilobyte (KB) (1024 bytes)Kilobyte (KB) (1024 bytes)Megabyte (MB) (Million bytes)Megabyte (MB) (Million bytes)Gigabyte (GB) (Billion bytes)Gigabyte (GB) (Billion bytes)Terabyte (TB) (Trillion bytes)Terabyte (TB) (Trillion bytes)Microprocessor (Processor)Microprocessor (Processor)Is an electronic circuit Is an electronic circuit designed to process designed to process instructions instructions Largest chip on Largest chip on motherboard motherboard Intel: world’s largest Intel: world’s largest chipmaker (Pentiums)chipmaker (Pentiums)AMD: Cheaper chips AMD: Cheaper chips (Athlons)(Athlons)Motherboard Motherboard Main circuit board Main circuit boardInside a typical desktop Inside a typical desktop computercomputerMicroprocessor (Processor)Microprocessor (Processor)All microprocessors have two All microprocessors have two parts: the arithmetic logic unit parts: the arithmetic logic unit ALU, and the control unitALU, and the control unit..ALU circuit performs ALU circuit performs arithmetic operations (e.g. arithmetic operations (e.g. addition), and logical addition), and logical operations (e.g. <).operations (e.g. <).ALU uses registers to hold ALU uses registers to hold data that is being processed.data that is being processed.Microprocessor (Processor)Microprocessor (Processor)The The control unitcontrol unit fetches each fetches each instruction.instruction.A microprocessor executes A microprocessor executes instructions that are provided by a instructions that are provided by a computer program.computer program.The list of instructions that a The list of instructions that a microprocessor can performed is microprocessor can performed is called its instruction set.called its instruction set.The microprocessor clock is a The microprocessor clock is a timing device that sets the pace timing device that sets the pace (the clock speed) for executing (the clock speed) for executing instructions.instructions.Microprocessor ComponentsMicroprocessor ComponentsMicroprocessor PerformanceMicroprocessor PerformanceSpeed: microprocessor clock set Speed: microprocessor clock set clock speed (MHz or GHz )clock speed (MHz or GHz )World Size: number of bits the World Size: number of bits the microprocessor can manipulate microprocessor can manipulate at one time (32-bit or 64-bit)at one time (32-bit or 64-bit)Memory Types Memory Types Random Access Memory Random Access Memory (RAM)(RAM)Virtual Memory Virtual Memory Read-Only Memory (ROM)Read-Only Memory (ROM)CMOSCMOSRAMRAMIs a temporary (volatile) holding area for data, Is a temporary (volatile) holding area for data, application software and operating system application software and operating system Expensive chip set Expensive chip set RAM is a temporary storage; disk storage is RAM is a temporary storage; disk storage is more permanent.more permanent.Less storage than disk Less storage than disk If the computer power is turned off, or if the If the computer power is turned off, or if the power goes out, all the data stored in RAM power goes out, all the data stored in RAM instantly and permanently disappears.instantly and permanently disappears.Capacity measured in MB (64 - 512 MB)Capacity measured in MB (64 - 512 MB)Random Access MemoryRandom Access MemoryRAMRAMVirtual Memory Virtual Memory Disk based Disk based If a program exceeds the allocated space If a program exceeds the allocated space in the RAM, the operating system uses an in the RAM, the operating system uses an area of the hard disk called virtual area of the hard disk called virtual memory.memory.Works with RAM, but is slowerWorks with RAM, but is slowerROMROM is a type of memory that holds start up is a type of memory that holds start up routine.routine.ROM contains a small set of instructions ROM contains a small set of instructions called ROM BIOS (Basic input/output called ROM BIOS (Basic input/output system). These instructions tell the system). These instructions tell the computer how to access the hard disk, find computer how to access the hard disk, find the operating system, and load it into the operating system, and load it into RAM.RAM.While RAM is temporary and volatile , While RAM is temporary and volatile , ROM is permanent and non-volatile.ROM is permanent and non-volatile.Read-Only MemoryRead-Only MemoryCMOSCMOSIs a type of memory that requires Is a type of memory that requires very little power to hold data.very little power to hold data.More permanent than RAM; less More permanent than RAM; less permanent than ROM.permanent than ROM.Complementary Metal Oxide SemiconductorComplementary Metal Oxide SemiconductorComputer File CharacteristicsComputer File CharacteristicsA collection of data on a storage A collection of data on a storage medium medium Filename conventions Filename conventions Filename extensionFilename extension.txt.txt.txt.txt.jpg.jpg.jpg.jpg.exe.exe.exe.exe.doc.doc.doc.docFile-naming conventionsFile-naming conventionsFile Locations File Locations