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72 Cards in this Set
- Front
- Back
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What is a CPU?
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It is a central processing unit. It interacts with input devices, main memory, and output devices.
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What is a microprocessor?
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It is a central processing unit on a single chip
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What are examples of things in a CPU?
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arithmetic and logic units, several accumulators, one or more registered stacks, and a control unit.
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What is an control unit?
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It fetches and decodes income instructions.
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what is the arithmetic and logic unit (ALU)
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It executes commands and manipulates data
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What are accumulators?
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It hold data and instructions for further manipulation in the ALU.
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What are registers
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used for temporary storage of instructions or data
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What is a program counter (PC)
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A register that always points to the the address to the next instruction to be executed
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What is the Instruction regist (IR)?
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It holds the current instruction during its execution
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What are stacks?
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It provides temporary data storage in sequential order.
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What is LIFO and another name for it?
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last-in, first-out, also known as pushdown stacks
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What are bus or channels
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They communicate with support chips and peripherals.
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what is the difference between bus or channel
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bus is the physical path, (wires or circuits), channel is the logical path
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what is the address bus?
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It directs memory and input/out device transfer
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what is the data bus?
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It carries the actual data and is the busiest bus
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what is the control bus?
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It communicates control and status information
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what is a bit-sliced microprocessor?
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It combines microprocesses (ex: 4 bit combined microprocesser for 16 bit)
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what is the purpose of a microprocessor clock?
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It control instructions and and data movements.
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what is the clock rate
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specifided in microprocessor cycles per second (ex: 600 MHz). Number of executions that can occur per second.
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what is a macrocommand
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command that requires one or more cycles.
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what are flops
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number of floating point operations that can be performed per second.
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what are mips?
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millions of instructions per second
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what are complex instruction set computing microprocesses (CISP)
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microprocessrs rich in complex executable commands (most micropproceesors).
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what is the purpose of a reduced instruction-set computing microprocessor
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increases operating speed and limited to performing simple, standarized format insturctions
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what is an operating system
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also known as monitor program. User interface and basic operation of computer. Also known as BIOS (basic nput/output system). Manages memory, schedules processing operations, accesses peripheral decies, counicates with use and resolve conflicting requirements for resources
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what is an interrupt?
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signal that stops execution of current instruction and transfers to another memory location.
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what is a bit
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binary digit of 1 or 0.
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what is a nibbles
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4 bits
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what is a byte
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8 bits.
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what is a halfword, words, and dourble words.
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8 and 16 bits
8 16 and 32 bits 16, 32, and 64 bits |
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how much do k, M and G represent
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2^10
2^20 2^30 |
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what is video memory
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It is known as VRAM and contains the text displayed on screen of a terminal. Screen refreshed many times per second, screen information repeadely read from video memory.
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what is cache memory
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It holds the most recently read and frequently read data in memory, making retrieval of data faster then reading from tape or disk drive.
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what is OS memory
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contains BIOS that is read when computer first starts.
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what is scratchpad memory
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high-speed memory used to store small amount of data temporarily so data can be retrieved quickly
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What is RAM, ROM, PROM and EPROm respectively
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Random accesss memory - easily changed
read-only memory - can not be altered programmable read-only memory - initially blanck but cannot be changed once filled erasable programmable read-only memory - initially blank but can be filled, rased and refilled repeatedly. |
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what is flash memory
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allows data to be written or ereased in block (EEPROm requres it to be replaced one byte at a time).
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what is firmware
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They are programs stored in ROM and EPROMs
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what is volatitle memory
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lost when the power is turned off. RAM is volatile.
ROM, PROm and EPROM are nonvolatile. |
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what is difference bewteen static and dynaic meory
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static - data does not need to be refreshed and remaisn as long as power stays on
dynamic- data must be continually refreshed. |
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what is SDRAM
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sycnchornous DRAM that runs higher clock speed then conventional memroy.
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what is RDRAM
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rambus DRAM, fastest memory technology currently avaialbe in personal computers. 100 Mhz.
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what is virtual memory
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programs and data larger than main memory can be accessed by the computer. slower occurance. Disk space used as exctension of semiconductor memory. Divided into pages.
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what is thrashing
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occurs when a program references a different page for almost every instruction and not enough real memory to hold virtual meory
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what is DMA
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direct memory access, allows peripherals to transfer data directly in and out of memory without afecting the CPU>
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what is parity
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technique used to ensure that the bits within a memory byte are correct. It is the nith bit in every eight bit. Constitutes a frame.
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what is odd and even praity recording
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parity bit will set so there is an odd number of one bits in the frame. Even parity is when there is an even number of one bits. in the frame.
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what is a parallel interface
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there are as many seperate lines in the cable as bits.
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what is serial interface
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all bits pass one at a time along a single line in the cable.
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what is transmission speed (baud rate)
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measured in bps, nuber of bits that pass through the data line per second
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baud rate
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one modulation per second.
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what is flow control or handshaking of peripherals such as terminals and printers
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sending the status of its buffers (small memoeries) (i.e, full, empty, off-line, etc.)
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what is software flow control or software handshaking?
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when characters are sent between the computer and peripherals so each send and receive data.
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what is hardware handshaking or harware handshaking?
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peripehrals keep voltoage on one of the lines high when it is able to accept more data. Computer monitors voltage
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what are muliplexers
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can be used to carry data for several peripherals along a single cable known as a composite link
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What is Frequency divison multiplexing (FDM) and
Time division multiplexing (TDM) |
FDM - available transmission band is divided into narrower bands, each used for a separate channel
TDM- connection channel operated at higher clock rate. |
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What is a random access(DIRECT ACCESS) STORAGE DEVICE/MASS STORAGE DEVICES
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individual RECORDS CAN BE ACCESSED WITHOUT HAVING TO READ THROUGH THE ENTIRE FILE.
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what are hard drives
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magnetic disk drives composed of several platters. Each platter has one or more read/write heads. It turns at high speeds (e.g thousands of rpm). Data on surface are organized into tracks sectors and cylinders
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What are tracks, sectors, and cylinders
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tracks concentric storage areas
sectores - pie-shaped subdivisions of each track cylinders - consists of same numbered track on all drive platters |
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what are to forms of optical disk revies
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read/only and read/write (WORM drives -write once read many_.
CD-ROM (compact disk read-only memory). |
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Name some paramaters used to describe performance of a disk drive
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storage capacity (sepcified in megabytes)
area density - measure of number of data bits stored per square inch of disk surface average seek time - average time it takes to move a head from one location to a new location track-to-track seek time - time required to move a head fro one track to an adjacent track Latency or rotional delay - time it takes for a disk to spin a particular sector under the head for reading average access time - time to move a new sector and read the data |
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what is a sequential access device
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A tape. Computer cannot acces information stored at the end of tape without reading information stored at front of tape
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what is an indexed sequential format
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Tape in which directory of files is place at start of tape.
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what is the difference between real-time and batch processing?
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Bach processing - all jobs of a particular type are bached together for subsequent processing. No interaction between user and computer.
Real tie (interactive) processing is a program runs when it is submitted, interacting with user during processing |
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What is a virtual machine?
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Main memory is allocated amoung several users running applications simultaneously.
Also known as multitasking and multiprogramming. |
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what is time-sharing (swapping)
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technique where each user takes turns using entire computer main memory for a certain length of tie.
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what is foreground processing
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program run in real time.
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what is background processing
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program continues to run unseen in the background accomplished by segmenting main computer memory.
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what is teleprocessing
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access of a computer from a remote station, usually over a telephone line.
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what does a modem do?
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converts digital signals required by a computer
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what is Local area network
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many identical computers are linked together in order to share storage and prining resources
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what is a distributed data processins system
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assumes many conficutation
traditional configuration - central main computers interacs with and is fed to small computers. second configguration is LAN |
