Introduction To Computing And Internet Computer Science Essay

Question 1

An component or device that is responsible for transition of the informations format that is suited for human communicating to a format that is acceptable for the computing machine is an input device.

An input device is a peripheral ( a device that is connected to the computing machine ) that is used to pass on between the user and the computing machine. It converts the user 's information input and converts it into a linguistic communication which the computing machine can understand.

[ 1 ]

Examples of an input device: Keyboard, Mouse, Scanner.

An component or device that converts the information back from a computing machine oriented representation to what is suited for homo is an end product device.

An end product device is a peripheral that is used to pass on between the user and the computing machine. It receives informations from the computing machine and change over it into a signifier which the user can understand. [ 1 ]

Examples of an end product device: Proctor, Printer, Speaker.

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An component or device that is the chief resource which holds both the plans and informations is the memory.

A memory shops plans and informations temporarily or for good. There are two types of informations storage, short-run informations storage and long-run informations storage. Short-run informations storage shops informations that are being processed by the computing machine. Long-run informations storage shops data that the users can recover. [ 1 ]

Computer memory is organized into a hierarchy harmonizing to the entree clip.

Untitled-1.png

Figure 1.1

( Adapted from Ryan J. Leng, 2007 )

The diagram above shows that processor registries have the fastest entree clip among the remainder.

Next in the hierarchy are the L1, L2 caches. Next is the chief memory.

These are the internal memory of the computing machine system. Below the group of internal memory in the hierarchy comes the external memory. External memory is able to hive away informations at a inexpensive rate but its entree clip is slower than the internal memory.

Example of internal memory: Random Access Memory ( RAM ) .

Example of external memory: Difficult Disk Drive.

An component or device that fetches instructions from chief storage, interprets them and issues the necessary instructions to assorted parts of the computing machine system is the control unit.

The control unit provides control signals and clocking to direct operations. It controls operations by directing out control signals to assorted parts of the system to execute certain maps. [ 1 ]

An component or device that conducts arithmetic and logical calculation is the arithmetic logic unit ( ALU ) .

The ALU is the nucleus of the cardinal processing unit ( CPU ) . The control unit sends signal to the ALU to treat the information. ALU performs operations such as add-on, minus, generation, division and Boolean logic. [ 1 ]

Block Diagram of Communication Between Devices: blockdiagram.jpg

Figure 1.2

( Adapted from William Stallings, 2010, Page 19 )

User inputs from the input equipment under the I/O equipment block are sent as instructions together with informations to the arithmetic logical unit ( ALU ) and command unit ( CU ) .

When treating the input from the I/O equipment block, the ALU communicates with the CU by interchanging instructions, informations and signals.

Processed informations will be stored in the internal memory temporarily. Based on the nature of the work, the informations storing may non be in the internal memory all the clip.

After the processing of information has been finished, informations is so retrieved from the memory and storage block.

The ALU and CU will so pass on between them by interchanging instructions, informations and signals while treating the end product from the memory and storage block.

The processed informations will so be sent back to the end product device under the I/O equipment block with direction, informations and signals.

Question 2

Measure 1:

Since the mark spot is 1, this tells us that it is a negative denary figure.

Measure 2:

The advocate 1000 0000 is in colored surplus, therefore the value is:

27 - 127 = 110

Measure 3:

The fixed-point part is 1.1 and it is negative, hence the information will be:

-1.1 x 21 = -112

Measure 4:

The binary value is so converted to denary which the decimal value is:

- ( 21 + 20 ) = -310

Question 3

Decimal value given: -1.26

Measure 1:

The negative mark tell us that the mark spot is 1.

Measure 2:

We so convert 1.26 to binary value which will be:

1.26 = 1.010001010001111010111 x 20

Measure 3:

Since 1.010001010001111010111 ten 20 is already in drifting point notation and the advocate is 0, biasing it will give us 0111 1111.

Measure 4:

Therefore the IEEE754 individual preciseness format of -1.26 is:

Sign

Advocate

Significand

1

0111 1111

0100 0010 1000 1111 0101 110

Chronological Order

1

2

3

4

5

6

7

8

9

10

Action Number

Bacillus

F

Calciferol

Tocopherol

I

A

Gram

Hydrogen

C

Joule

Question 4

scheduling.jpg

Figure 4.1

( Adapted from William Stallings, 2010, Page 276 )

Action B:

The petition for Process P is sent to the long term waiting line of the Operating System ( OS ) waiting to be procedure. A long term waiting line is fundamentally a waiting list of procedures waiting to utilize the processor.

Action F:

When there are sufficient resources for Process P to be processed, the long-run scheduler of the OS will apportion the memory to the petition of Process P and Process P is created.

The freshly created Process P is so sent to the short term waiting line. A short term waiting line is a list of procedures that are ready to be processed by the OS.

Action D:

In the short term waiting line, the short term scheduler will find which procedure to be sent into the processor to put to death. When Process P is being sent into the processor, the processor executes OS instructions and user procedures alternately.

Action Tocopherol:

Since Process P is a procedure that involves I/O operation, it will necessitate entree to the I/O device. Therefore, Process P is being moved to the I/O waiting line of the I/O device by the short term scheduler when the processor receives direction about I/O in Process P.

Action I:

Because the processor runs at a much faster velocity than the I/O operation, the processor will be idle at most of the clip. In order to cut down idle clip, the processor should hold some other procedures for it to transport out while waiting for the I/O response.

However, the chief memory is full. Therefore, Process P is swapped out of the chief memory to make some free infinite for other procedures.

Action A:

Process P, which is being swapped out of the chief memory by the average term scheduler to the intermediate waiting line is now shacking on disc while waiting for the I/O operation to be complete.

Action G:

When the I/O operation is completed, the I/O faculty sends an interrupt petition to the processor. The processor will suspend executing of its current procedure and ready to work on Process P.

Action H:

Procedure P is so moved from the I/O waiting line by the short term scheduler back into the short term waiting line for the processor to treat it.

Action C:

The intermediate scheduler barters Process P into the chief memory and the processor continues the executing of Process P from where it was stopped antecedently.

Action J:

When Process P is completed or being stopped by the user, it will be send to the terminal province. The OS will so cancel Process P from all the waiting lines.

Examples:

An illustration of this operation would be a printing occupation for the pressman. Assume the print occupation is Process P.

When the user selects the print bid on the computing machine utilizing either a mouse or a keyboard, a petition is send to the long term waiting line. When there are sufficient resources for the print occupation to be procedure, some memory are allocated to Process P from the chief memory. Following, Process P is send to the short term waiting line to wait for it to be process by the processor.

Process P involves an I/O operation. An I/O operation is much slower than the processor 's velocity and because there are other processes other than Process P within the processor, the processor may trade Process P to the intermediate waiting line. At the same clip, Process P is moved to the I/O waiting line of the I/O device because there may be other processes other than Process P that is waiting to entree the device. In this instance, Process P is a print occupation. Therefore, the I/O device is a pressman and the other procedures are other print occupations for the pressman to transport out.

When the bend for Process P to be printed is up, it is send to the pressman. As the publishing velocity of the pressman is much slower than the processor 's velocity, the processor will direct the informations pieces by frames while jumping with the processing of other procedures.

When the printing of Process P is completed, Process P will be stopped and direct to the terminal province. The OS so cancel Process P from all waiting lines.

Decision

The computing machine system is made up of major constituents. The major constituents are the processor, chief memory and the I/O equipments. The major constituents communicate with each other via informations and signals processed by the Arithmetic Logic Unit ( ALU ) and direct out by the Control Unit ( CU ) .

The computing machine system merely works on binary figures and IEEE 754 is a criterion for drifting point informations storage.

Operating System ( OS ) manages different procedures in the computing machine system by scheduling. There are four major types of scheduling. They are the long term programming, short term programming, average term programming and I/O programming. In the instance when there is an I/O operation, swapping is performed so as to increase the efficiency use of the chief memory for procedure executing.

Learning Outcome

First, we have learned about the assorted constituents in a computing machine system and how they work together and transport out a certain map.

Next, as the computing machine merely works on binary figures, we have learned how to stand for informations in IEEE 754 by change overing from a tenfold figure and frailty versa.

Last, we now understand the whole procedure of scheduling performed by the OS. Memory direction is besides another undertaking performed by the OS and both are of import in a concurrent execution system.