Chapter 5 and 7--components Flashcards
Nano, Pico, Micro, Milli, Tera, Giga, Kilo, and Mega–define, give exponents
nano–billionth/10^-9, pico–trillionth, 10^-12, micro–millionth, 10^-6, Milli, thousandth, 10^-3, Tera, trillion, 10^12, Giga, billion, 10^9, Kilo, thousand, 10^3, Mega, million, 10^6
FSB?
front side bus
ratio of binary exponents to decimal exponents
10 binary for every 3 decimal
define “peta”
Greek for 5
how many Gb can a Blue-Ray disc store?
25 or 50, depending on if it is dual layer (DL)
what type of CD format is used in Audio recordings?
CD-DA, compact disc-digital audio
How much data can a CD-ROM hold, and how big is a sector?
600 Mb, and 2KB
What do the plus and minus symbols denote in the names of DVD formats? What does DL stand for?
two different, competing formats. dual layer
what are the capacities of DVD-R and DL DVD-R?
4.7 and 8.5 GB
What do R and RW stand for in DVD names? What does the x stand for?
recordable and rewritable. speed of access of info on the disk
what year was the flash drive introduced, and who introduced it?
IBM, 1998
How fast do the hard disks in regular desktops, laptops, and high performance servers run?
5400, 7200, and 15,000 RPM
Discuss different types of touch screens
Resistive–has two layers, one with horizontal and the other with vertical lines of conductive material. Capacitive–conductive laminate over a glass screen, with current at all 4 corners. the relative strength of the current is measured at each corner, giving the location of the touch. Infrared–grid of infrared beams. Surface Acoustic Wave–ultrasonic sound waves across the screen.
How do embedded systems usually store their programming? Do they have OS?
in ROM. Some are so simple that they don’t require OS
discuss processor history in embedded systems, and discuss what languages are used in them.
early ones were 8-bit with homegrown OS. now there are 32-bit DSP (digital signal processors) and 64-bit RISC chips. Assembly language is usually used, but sometimes C. C is slower and larger, but easier to write in.
Instruction-level parallelism? superscalar?
instruction-level parallelism is running unrelated steps in a program simultaneously. A superscalar is a processor that can recognize this situation and take advantage of it. A superscalar machine does not have multiple processors, but may have multiple execution resources, like two ALUs, one for integers and one for real numbers. Such resources are called Execution Units.
Data-level parallelism? Synchronous processing?
Data-level parallelism–based on the idea that a single set of instructions can be run on different data sets at the same time. This is called SIMD, which relies on a control unit directing multiple ALUs to carry out the same operation on different sets of operands. This is also called “synchronous processing”.
Task-level parallelism?
based on the idea that different processors can execute different tasks on the same or different data sets. Each processor can perform a different stage of the calculations on a particular data set. It can also involve MIMD, which can cause problems of coordination among the processors. This is solved by each processor having both a local and a shared memory. This is called “Shared Memory Parallel Processor”.
SMPs?
Symmetric Multiprocessors have multiple identical cores, they share memory, and are connected by a bus. The number of cores in an SMP is usually limited to 32.
Distributed computer?
multiple memory units connected through a network
Cluster?
a group of standalone machines connected through an off-the-shelf network
Massively parallel processor?
computer with over 1000 or more networked processors connected through a specialized network.
Parallel computers used for science might use ____ processing, whereas a search engine computer might use more ____ processing. Task-level/data-level
data-level, task-level
Core 2 processor?
dual core
Stored-program concept?
The stored program concept means that data and instructions are both logically the same and can both be stored in memory. The von Neumann architecture is built around this principle.
components of a von Neumann machine?
memory, arithmetic/logic unit, input/output units, the control unit
Instruction register?
The instruction register is a special register in the control unit. It holds the instruction being executed.
Program counter?
The program counter is a special register in the control unit. It holds the address of the next instruction to be executed.
List steps in the fetch-execute cycle?
- Fetch the next instruction from the address in the program counter. 2. Decode the instruction.
- Execute the instruction.
Explain what is meant by “fetch an instruction.
The control unit goes to the address named in the program counter, makes a copy of the contents of that address, puts the copy into the instruction register, and increments the program counter
Explain what is meant by “decode an instruction.”
The control unit determines what the instruction is and accesses any memory locations that contain operands for the instruction.
Define what is meant by a block of data.
A block of data is the data stored in a sector of a disk.
4 measures of a disk drive’s efficiency
seek time, latency, access time, and transfer rate
Distinguish between a compact disk and a magnetic disk.
Rather than having a series of concentric tracks, a
compact disk has one track that spirals from inside out. Both disks have the track broken into sectors.
The density at which the data is packed varies in a magnetic disk, but does not in a compact disk. The
rotation speed of a magnetic disk reader is constant, but the rotation speed of a compact disk varies depending on the position of the laser
beam.
Describe a parallel architecture that uses synchronous processing.
multiple processors applying the same program to multiple data sets.
Describe a parallel architecture that uses pipeline processing.
Multiple processors are arranged in tandem. Each processor contributes one part of the overall processing.
How does a shared-memory parallel configuration work?
Multiple processors do different processing with different data but communicate through the use of shared global memory.
How many different memory locations can a 16-bit processor access?
2^16, or about 65K
What does DDR2 refer to in RAM?
Double-data rate, 2nd generation
SATA?
Serial ATA, versus the older parallel ATA, which used multiple wires. ATA refers to a way of attaching a hard drive to the old IBM PC/AT, from 1984.
IEEE 1394?
FireWire
Pico, nano, micro, milli, kilo, mega, gigs, Tera, peta–give languages and defs AND abbreviations
Pico–Italian for small, rest are Greek except for milli, which is Latin for thousandth. Nano-dwarf, micro-small, kilo-thousand, mega-large, giga-giant, Tera-monster, peta-5. Abbreviations are the first letter, except micro which is mu. Big ones are caps
John Vincent Atanasoff–accomplishments and awards.
National Medal of Technology. ABC machine (Atanasoff Berry Conputer)
Discuss Fetching an instruction in detail.
Control unit goes to the addy in the Program counter, copies the contents, and puts them in the instruction register. Then the control unit updates the PC.
The instructions are stored contiguously, so adding the number of bytes in the current instruction to the PC gives the address of the next instruction. This is how the control unit updates the PC.
It is also possible that the PC may be updated later by the instruction being executed.
If an instruction needs additional data from memory, the ALU sends an address to the memory bus, and the memory responds with the value at that location.
The data retrieved from memory can either immediately be used in arithmetic or logic, or it can be stored in a register, depending on the computer.
discuss decoding an instruction.
the control unit decodes the instruction into control signals that are in the machine language of the computer. The instruction may also require the control unit to get a value from memory.
Discuss executing an instruction.
once the instruction has been decoded and any operands fetched, the control unit instructs the ALU to do the processing. If a number is being added to a register, the operand is sent to the ALU and added to the contents of the register.
When the cycle is complete, it begins again. If the last instruction was to add a value to the contents of the register, the next instruction probably says to store the results in memory. However, the next instruction might be a control instruction, which would ask a question about the result of the last instruction and possibly change the contents of the program counter.
Main memory of a computer contains what type of memory?
usually both ROM and RAM
how much music does a sector of a CD-DA contain?
1/75 of a second.
how is the memory on a hard disk organized?
into tracks and sectors. As time has passed, there have been fewer sectors toward the center of a disk, and more toward the outside.
Discuss latency for disk access, and give another name for it.
also called rotation delay, the average latency is 1/2 the time for a full disk rotation. Also known as the time it takes for a sector to be in position
discuss seek time.
Seek time is the time it takes to get the correct TRACK under the read/write head. Track track track
discuss access time.
Access time is the sum of seek time and latency.
How fast can serial ATA transfer info?
Up to 300 MBPS
Who probably originated the stored-program concept?
Credited to Von Neumann, but probably started with J. Presper Eckert and John Mauchly
Most computers today are _____ addressable.
Byte
What does it mean to say a machine is n-bit addressable?
N usually refers to the number of bits in the CPU General registers: so two n-bit numbers can be added with a single instruction. It can also refer to the width of the address bus, which is the size of the addressable memory, but not always.
It can even refer to the width of the data bus– but not always.
Big book on problem solving–title, author, date
George Polya, 1945, “How To Solve It: A New Aspect of Mathematical Method”.
4 phases of the computer problem-solving process. Give outputs.
Analysis and specification phase–results in a clearly-written problem statement. algorithm development phase–results in a general solution to the specified problem. implementation phase–results in a working computer program. maintenance phase–no result unless there are changes that need to be made, or errors are found.
Define data abstraction, procedural abstraction, control abstraction, and control structure. Give examples.
Data abstraction–the separation of the logical view of data from its implementation. Binary vs. decimal readouts
Procedural abstraction–the separation of the logical view of an action from its implementation. The use of a Subprogram
Control abstraction–the separation of the logical view of a control structure from its implementation.
Control structure–a statement used to alter the normally sequential flow of control. Commands in a programming language like “while” and “if” are control structures
George Polya Prize?
For notable application of combinatorial theory
Count-controlled loop? Name and define parts
A loop that repeats a process a specified number of times.
Loop Control Variable–is initialized to a starting value, then tested to see if it has reached a predetermined value, then incremented by 1.
Event-controlled loop?
In which the number of repetitions is controlled by an event that occurs within the body of the loop itself.
Nested structures?
One control structure imbedded inside another one
Abstract and concrete steps?
Abstract steps need to be expanded further (they have unspecified details.) Concrete steps cannot be expanded.(no details remain specified(
Array?
A named collection of homogeneous items in which individual items are accessed by their place in the collection
The types of algorithms with arrays–name and define.
Searching, sorting, and processing–all other computing done with arrays that isn’t searching or sorting
Record?
A named heterogeneous group of items in which individual items are accessed by name.
Binary search?
Assumes items in the array are sorted, and either finds the item or eliminates half the array with one comparison. It begins in the middle, and stops when the item is found or when the portion of the array where the item might be found is empty.
What is a cylinder?
All of the tracks that line up under one another on a hard disk
Who developed ENIAC, when, where?
Mauchly and Eckert, U. Of PA, 1945
Strategy used in the Quicksort algorithm
Split list into two parts and then do the same for each smaller list, etc
Can selection structures be nested?
Yes
Can all control structures be nested?
Yes
The square root algorithm uses a count-controlled loop. T/F
False
When are binary vs linear searches faster?
If the array is sorted, binary searches are faster if there are more than 20 items
A selection sort does what?
Moves the smallest item to the top of the array, and puts the item that was previously there in the now-empty spot
An insertion sort puts 1 more item into place with respect to the already-sorted portion. T/f
True
Which other type of sort uses the bubble sort technique?
Insertion sort
Recursive algorithm?
Uses its own name within itself. Uses a selection statement to determine whether to repeat the algorithm again.
Each one has at least 2 cases: base and general. The base case is the one that we have an answer to. The general case expresses the solution as a call to itself with a smaller version of itself
Calling unit?
You can give a section of code a name and then use that section in another part of the program. When the name is encountered, the the processing in the other part of the program halts while the names code executes. When the named code finishes executing, processing resumes with the statement just below where the name occurred. The place where the name appears is called the calling unit.
Recursive algorithms use “if” statements. T/F
True
Iterative algorithms use “while” statements. T/f
True
List the 4 steps in Polya’s list
Understand the problem.
Find the connection between the data and the unknown. You may need to consider auxiliary problems. You should obtain a PLAN of the solution.
Carry out the plan, checking each step.
Examine the solution, check the result if possible
Difference between top-down design and object-oriented design.
Polya’s method is hierarchical/top-down design. It produces a hierarchy of tasks to be solved.
Object-oriented design produces a hierarchy of data objects.
Identifiers?
Names within a specific programming language for data and activities
Tony Hoare?
Quicksort and Turing award, and a knighthood. Retired from Oxford, works at Microsoft
Two types of subprograms?
Named code that does a particular task (void) and named code that does a task AND returns a single value to the calling unit (value-returning subprograms)
The while loop in a count-controlled loop is called a _______
Pretest loop, because it takes place before the loop is executed
3 parts of process when using a while statement in an event-controlled loop?
Event must be initialized, tested, and updated
Sequential search in an unsorted array ends when?
When the item is found, or when all items have been looked at without a match
CD-WORM?
Write once, read many
DVD?
Digital versatile disk
Simple versus composite data type. Give example .
Composite type contains more than one value, a string is an example
Give 2 composite data-structuring mechanisms.
Arrays and records
Sort key?
The field(s) on which the ordering of a sort is/are based
When does a sequential search in a sorted array end?
When you have looked at the place where the item should be
