Computing Systems

Question 1

Define Hardware

Answer 1

provides the physical mechanisms to input and output data, manipulating data and controlling the various input, output, storage and communications components.

Question 2

Define Software

Answer 2

both application and system, which provides instructions that tell the hardware exactly what tasks are to be performed and in what order.

Question 3

How is data represented for a computer? ie in what form/s.

Answer 3

can be alphanumeric, graphic or any other form. In all cases it is represented in a form that the computer will understand and manipulate.

Question 4

What is the architecture in computing systems?

Answer 4

It refers to those attributes of a system visible to a programmer. The architecture of a CPU is its instruction set, number of bits used for data representation, addressing techniques etc

Question 5

What is the organisation in computing system?

Answer 5

It refers to the operational units and their interconnections that realise the architectural specification . Hardware details transparent to the programmer, such as control signals between different functional units, memory type etc

Question 6

Name the two approaches that are used in computing systems, and which is clearest and most effective.

Answer 6

Top-down approach-starting from a top view and decomposing the system into its subparts. (Clearest and most effective)
Bottom-up approach- starting from the bottom and building up a complete description

Question 7

What is the structure and the function of computing systems?

Answer 7

Structure-the way the components are interconnected
Function-the operation of each individual component as part of the structure

Question 8

Name and give examples of 4 computing systems functions.

Answer 8

1. Data processing-fundamental types of data/processing
2. Data storage-Short/Long term strorage
3. Data movement-Input/Output for devices directly connected. Data communication for moving data over long distances
4. Control-External (users)/Internal (manage resources)

Question 9

What is the difference between analog and digital data representation?

Answer 9

Analog data is a continuous representation, analogous to the actual information it represents. eg mercury thermometer.
Digital data is a discrete representation, breaking the information up into separate (discrete) elements.

Question 10

Why is digital data mainly used ?

Answer 10

Both electronic signals degrade as they move down a line. The voltage of the signal fluctuates due to environmental effects. As soon as an analog signal degrades, information is lost. However, digital signals jump sharply between two extremes. A digital signal can degrade quit a bit until the information is lost.

i.e. signal integrity can be maintained in digital signals.

Question 11

What can be done to digital and analog signals to regain its original shape after degradation?

Answer 11

They can be reclocked before too much degradation occurs so no information is lost.

Question 12

Why is Binary representation used?

Answer 12

Because devices that store and manage the digital data are far less expensive and complex for binary representation. They are also far more reliable and electronic signals easier to maintain.

Question 13

What does ASCII stand for

Answer 13

American Standard for Computer Information Interchange

Question 14

How many characters can the original ASCII and extended ASCII represent?

Answer 14

original-128
extended-256

Question 15

Explain what unicode is

Answer 15

Since the extended ASCII is not enough for international use, Unicode is a character set that can represnt 2^16 characters(over 65,000). The first 256 characters correspond to the extended ASCII set.

Question 16

Explain Overflow

Answer 16

Overflow detects errors in signed (i.e. represents both positive and negative numbers) arithmetic operations. i.e. when the result of the calculation doesn’t fit into the fixed number of bits available for the result.

Question 17

Explain Carry

Answer 17

Carry detects errors in unsigned (i.e. non-negative numbers) arithmetic operations. It occurs when you cannot properly represent the result as an unsigned value.

Question 18

What are floating point numbers?

Answer 18

Real or floating point numbers are used in computing systems when the number to be expressed is outside of the interger range or when the number contains a decimal fraction. The number is represented by a fixed number of digits of precision together with a power that shifts the point to make the number larger or smaller.

Question 19

What is meant by exponential notation?

Answer 19

Exponential notation is simply representing a number in the form A * 10^c, where A is a number that is multiplied by 10 x times. The exponent, x, can be either negative or positive.

Question 20

Explain what is meant by SEEMMMMM

Answer 20

S- one digit to represnt whether it is negative (5) or negative (0)
EE- two digits to represent the exponent ie >50 = positive, <50 = negative eg 53 = 3 while 47 = -3
MMMMM- The mantissa representation i.e. the numbers

Question 21

What is normalization?

Answer 21

When necessary, numbers are shifted left byb increasing the exponent until leading zeros are eliminated. eg .MMMMM * 10 ^ EE
For example:
take 246.8035 * 10^0
Shift the decimal point to the right or left by increasing or decreasing the exponent – .2468035 * 10 ^ 3
then format the number – 05324680
(note that the 35 at the end of the number are cut off as it only takes 5 numbers after the decimal point)

Question 22

Explain what is a synchronous clocked sequential circuit

Answer 22

a digital circuit in which the changes in the state of memory elements are synchronized by a clock signal.