Final to remember

Question 1

What is a hard disk?

Answer 1

Hard disks consist of several magnetic disks stacked on top of each other, each with their own read write head. Each disk is connected to a spindle that rotates them all simultaneously. All the tracks lined up under each other is called a cylinder. An address consists of the cylinder number, surface number and the sector. Hard drives rotate much faster then floppy disks at around 7200 RPM. Laptops spin slower at around 5200 RPM to conserve power.

Question 2

What is sampling?

What is quantisation?

Answer 2

Sampling is the process of periodically measuring the voltage level of a sound. When sampling, it should be done 40,000 times per second to produce a reasonable representation of the sound.
quantisation is representing the voltage level as a number using finite bits.

Question 3

What is a CD? and what are the acryoynms?

Answer 3

A compact disk that uses a laser to read information stored optically on a plastic-coated disk; data is evenly distributed around spiral track.

CD-ROM read-only memory
CD-DA digital audio
CD-WORM write once, read many
RW or RAM both read from and written to

Question 4

What is a DVD?

Answer 4

Digital Versatile Disk, used for storing audio and video. can usualyy store 4.75GB
DVD-DL: dvd duel layer.

Blu-ray
Higher capacity DVD allowing higher resolution video, and can store about 25GB. Uses a blue laser isntead of a red one

Question 5

What are flash drives?

Answer 5

Flash drives are non-volatile computer memory. They are often fitted with a USB (universal serial bus). Flash memory is also used to build SSD, which is a lot faster then hard drives. It also consumes less power then hard drives due to it not having moving parts. However, its storage units still wear out, meaning they can suffer from failures just like hard drives.

Question 6

What is an integrated circuit?

Answer 6

A piece of sillicon in which gates are embedded. Tis is mounted onto a piece of plastic or cermainc, and has pins along the edge which can be solderd to circuit boards. Each pin connects to the input or output of a a gate, or the power or ground.
In VLSI the gates are not independent as they are in SSI. They have a high gate to pin ratio.

Question 7

How does a avlue get stored in an S-R latch?

Answer 7

We set the value to 1 momentarily setting s to 0 while keeping r at 1. if r is 0 y becomes 0 so the state remains 0.

Question 8

What do the assembly code instructions do:
BRLT
BREQ

Answer 8

BRLT: set the PC to the operand if register A is less than 0
BREQ: set PC counter to the operand if the A Register is equal to 0.

Question 9

What is bit level parallelism?

Answer 9

Bit-level parallelism: This is based on being able to processor more bits at once. This can be done by increasing the word length, meaning more bits can be processed simultaneously. This can result in less tasks needed to be performed. Current computers compute 64 bits at once

Question 10

What is instruction level parallelism?

Answer 10

Instruction level parallelism: This is based of being able to perform instructions that operate on unrelated data at the same time. One method of doing this is by using a super scaler processor which can recognise this situation and send the different instructions to different functional units so the instructions can be carried out independently at the same time. Note there is only one processor, but it has multiple execution resources.

Question 11

What is data level parallelism?

Answer 11

Data level parallelism: This involves performing the same instructions on data, on different sets of data at the same time. This type is typically called SIMD and relies on a control unit directing multiple ALU’s to carry out the same operation on different sets of operands. This approach is also called synchronous processing.

Question 12

What is task level parallelism?

Answer 12

Task level parallelism: based on the idea that different processors can perform different tasks on the same data sets r on different data sets at the same time. If the different processors are operating on the same data set, then it analogous to pipe-lining in von Neuman archetexure.

Question 13

What is pipeling?

Answer 13

A method in von neaumon architecture to speed up the fetch execute cycle. It involves breaking a task down into smaller steps that can be overlapped.

Question 14

What is an embedded system?

Answer 14

An embedded system is a computer that is designed to perform a specific function as part of a larger system. They are typically stored in ROM on a single microchip. Most digital appliances that have an interface have an embedded system.

Question 15

What does FSB stand for?

Answer 15

FSB stands for front side bus, the primary connection between main memory and input/output devises.

Question 16

Punched cards and paper tape were early input/output mediums. Discuss their advantages and
disadvantages.

Answer 16

Punched cards and paper tape used for input were prepared on separate machines and then read into
the computer. Input from cards and paper tape is slow, but they provided a permanent record of the
input. When used for output, cards and paper tape had to be transferred to another device to get a
human readable copy of the information; however, the output could be stored permanently on cards
and paper tape.

Question 17

What are the steps of the fetch execute cycle?

Answer 17

Fetch the 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.
decode The instruction:
The control unit determines what the instruction is and accesses any memory locations that contain
operands for the instruction.
execute the instruction:
Signals are sent to the arithmetic/logic unit to carry out the processing.

Question 18

Compare ram and rom

Answer 18

-Both are random access; that is, each cell in memory is directly accessible.
-Thecells in RAM can be both read from and written to. —The cells in ROM can only be read from. The
bit pattern in ROM is determined at the time of manufacture or burned when the computer is
assembled. Once a ROM has been burned (written), it cannot be changed.
- RAM is volotile, ROM is not.

Question 19

Discuss the pros and cons of using magnetic tape as a storage medium.

Answer 19

Magnetic tape is a cheap medium for storing great quantities of data. However, data items cannot
be directly addressed on tape. To reach a data object, all information recorded before the one you
want must be read and discarded.

Question 20

What is a secondary storage device?

Answer 20

RAM is volotile so loses the data stored when power is lost, and ROM can not be written too so computers need other methods to store data apart from main memory. These are called secondary storage devices.

Question 21

Pros and cons of the magnetic tape?

Answer 21

+ a cheap method of storing large amounts of data.

- when accessing a data element, all preceding elements have to be read and discarded.

Question 22

What are the advantages and disadvantages of the punch card and paper tape?

Answer 22

.Used as inputs

Question 23

Similarities and differences of the CD and the magnetic disk?

Answer 23

• CD reads data optically but the magnetic disk reads data magnetically.
• CD stores data in a continuous spiral, but a magnetic disk stores data in concentric circle.
• The density of the data on a magnetic disk varies, but stays constant for CD
• Both disks have the tracks broken down into sectors.
• the speed at which the magnetic disk rotates stays constant, but varies on a CD depending on the position of a laser.

Question 24

Describe a parallel architecture that uses synchronous processing.

. Describe a parallel architecture that uses pipeline processing.

Answer 24

There are multiple processors applying the same program to multiple data sets.

Multiple processors are arranged in tandem. Each processor contributes one part of the overall
processing.

Question 25

What is a loader?

Answer 25

A piece of software that a machine language program and places it in memory.

Question 26

What is an assembler?

Answer 26

A program that translates an assembly language program in machine code.