Introduction to Computers Section 4A

home Decimal Number System Called base 10 because 10 symbols are available

home Binary Number System Computers function in base 2, or the binary number system, where there are only two values

home Bit A combination of binary digit The smallest possible unit of data a computer can recognize or use

home Byte A group of eight bits

home Text Codes EBCDIC ASCII Unicode

home CPU The CPU is the computers brain that manipulates data

home CPUs Two Basic Parts Control unit Arithmetic logic unit

home Control Unit Manages all the computers resources

home Arithmetic Logic Unit Performs the CPUs arithmetic and logical operations

home Machine Cycle The completed series of steps the CPU takes to execute an instruction

home Machine Cycles Two Cycles Instruction cycle Execution cycle

home Instruction Cycle Fetching Decoding

home Execution Cycle Executing Storing

home Millions of Instructions Per Second (MIPS) The CPU performance measurement

home Pipelining Also called pipeline processing The control unit begins a new machine cycle before the current cycle is completed

home Memory Allows the CPU to store and retrieve data quickly

home Two Kinds of Memory Read-only memory (ROM): nonvolatile Random-access memory (RAM): volatile

home ROM ROM always holds the same data, for example the computers start-up instructions

home RAM RAMs job is to hold programs and data while they are in use RAM can change instantly

home Other Kinds of RAM Dynamic RAM (DRAM) DRAM Variations Static RAM (SRAM)

home Factors Affecting Processing Speed Registers Memory and computing power System clock The bus The databus The address bus Cache memory

home Bus Types Industry standard architecture (ISA) bus Local bus Peripheral component interconnect (PCI) bus Accelerated Graphics Port (AGP) bus Universal Serial Bus (USB) IEEE 1394 (FireWire)

home Data Transfer Rate The amount of data buses can transfer in a second Measured in megabits per second (Mbps) or megabytes per second (MBps)

home Cache memory Speeds processing by storing frequently used data or instructions in its high- speed memory

Section 4A Transforming Data Into Information

home Review Questions What is the difference between a bit and a byte? What are the CPUs two basic parts? What is a machine cycle? What is the difference between ROM and RAM?