The effects of interent on families and employment

The Internet has GREATLY affected both families and employment globally. It has allowed families to communicate over long distances far more eaily through services such as Skype. Also, photographs can be shared through socail media sauch as Facebook which negates the need for old skool film being developed. However, a negative for parents would be that the likelihood of their children being targeted by paedophiles. Homework can also be done on the internet.
Employers have also been affected since the beginning of widespread usage of the internet. Employees can work from home meaning more work can be carried out, benefitting the business greatly. However, the business has no way of monitoring how much work is being done. E-Commerce websites such as eBay and Amazon have also become more promminent as people can shop from home without leaving their house and the product is delivered straight to their door. Video conferencing with foreign countires ihas also become more popular.
Basically, the internet is very good adn it has improved everyobdys lives greatly muchly. It also coimes with some drawback but the positives outweigh the negatives and then some.

Input and Output Devices

Keyboard:

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The Processor

The processor is the most essential part of the calculator and is often referred to as its ‘brain’. It carries out all the computers operations and tasks but while only being able to do one task at a time, it does them very very fast! 

The processor has 4 main components: the ALU; the Control Unit; the Memory Address Register and the Memory Data Register. Along with these there are a few other smaller registers.

ALU stands for Arithmetic Logic Unit. This does all of the calculations and performs logical operations using AND, NOT and OR gates. The Control Unit is the part of the processor that manages the fetch and execute cycle. This is the process of carrying out the tasks. Registers are very fast, temporary which hold the address of the data (in the MAR) and the data itself in the MDR. 

There are internal buses which are used to transmit the data from component to component. The main three buses used are the Address bus, Data bus and Control bus. 

Bit – Mapped Graphics

A pixel is just a tiny  dot on the computer screen. The resolution determines the quality of the picture so the finer the pixels, the better the resolution. Black and white images are represented in binary with a ‘0’ being used to show white and a ‘1’ is used to show black. A colour bit-mapped image uses 2 bytes of data to store each colour so up to 65,535 colours can be represented. 

 

Data Representation – Binary

The word  binary is derived from the word ‘bi’ which means two. This is relevant as binary is a number system that can only have two possible values, so it has a base of 2. It is used in computer systems because of the fact that computers operate on electrical signals and it is much easier for the computer to only be able to recognise 2 signals (on or off / any voltage or no voltage) than possibly ten signals if it were to use decimal like humans do. Believe it or not, the only reasons humans do actually use the decimal system (which has a base of 10) is because we have ten fingers!

The smallest unit of measuring binary is a ‘binary digit’ or more commonly known as a bit. These are very small and the next biggest unit of measurement is a byte, which is still not that big and is made up of 8 bits. You then continue going up in the scale of powers of 2 until you come to 1024 bytes, which would equal one Kilobyte (kB). Then, there is 1 Megabyte (MB) which is 1024 kilobytes. This would store maybe about 3 minutes of mp3.

Of course, humans cant understand raw binary so we need to convert it to something we understand such as decimal. For example,

128     64     32     16     8     4     2     1
1          0       0        0      1     0    1      1

The number 10001011 in 8 bit (1 byte) binary would equal 139. Every time there is a 1 in binary below a number, you add that number to your total to calculate the decimal.

 

Negative numbers are more commonly represented using Two’s Compliment Representation. You do this by taking the original positive binary number, changing all the zeros to ones, ones to zeros and then adding one on at the end.

 

R.I.P Steve Jobs

Born on February 24 1955, Steve Jobs was an American visionary, inventor and entrepreneur. He was the co-founder of Apple Inc. and was also on the Board of Directors of Disney. Since 1974 to the day he died, Jobs racked up a net worth of over $7 billion through the creation of modern-day essentials such as the iPod, iTunes, the iPhone and the iMac series. In true spirit, Jobs worked right up until the only six weeks before he died with the iPhone 4S due to be released on the 14th of October this year.

After a 7 year long battle with pancreactic cancer and also liver complications, Steve Jobs sadly passed away on October 5 2011 aged only 56. Many people have said that in years to come, he will be seen in the same light as Albert Einstein for the revolutionary work he carried out…

R.I.P Steve Jobs.

Macros, Scripting and Modularity

A high level programming language is more like the English language. It uses words such as, If, Then, Else. This is easy for humans to understand as it resembles English but you could not write a program in  this language . Commands are translated into a low level language for the computer to understand such as binary.

A macro is created by the user actually recording it themselves. This is a huge advantage as, if you have good knowledge of the program, it can be made to do anything you like and can be assigned to key strokes e.g CTRL + SHIFT + T. Scripts are different as they consists of commands that are predefined by the programmer. The user simply selects the order in which to execute these commands and assign them to a keystroke. This is a big advantage as the user does not need an in depth knowledge of the program.

There are two different types of parameters, Actual parameters and Formal parameters.Formal parameters are the parameters that are used in the subroutine definition are formal parameters.  Actual parameters are passed into a subroutine from another part of the program.

Documentation, Evaluation & Maintenance

Documentation:

Documentation is used to help the user learn to use the program and to help them understand it. There are 2 standard types of Documentation and these are the User Guide and the Test Guide. The User Guide explains how to use the software and in the past often came in paper form but nowadays comes more often in an electronic file or online help. The Technical Guide informs the user about information such as how to install the software, the memory and processor requirements of the program, the version of the program and details of any add-ons or other applications that may need to be installed.

 

Evaluaiton:

The Evaluation stage requires the developer and the client to review the software and they do this by checking the software against two questions:

1. Is the program fit for purpose?

2. Does the program meet the software specification?

To answer these 2 questions, the program is evaluated against the following conditions:

  • Robustness => it will not fail or crash no matter what is inputted.
  • Reliability => it will always show the correct output.
  • Portability => it can be run on other operating systems than what it was designed on.
  • Efficiency => it takes up as little RAM and processor space as possible so that other programs may be run at the same time.
  • Maintainability=> it can be changed easily for whatever reason, possibly even by another programmer.

 

Maintenance:

Maintenance is the final stage of the software development process!! This is because it can only be done when the program is finished and it is constantly happening. There are 3 types of Maintenance: Corrective; Adaptive and Perfective. Maintenance can become difficult when there is a software environment change. An example of this could be an update of Operating Systems or a change in Hardware.

 

 

 

 

 

Testing

Although Testing is the fourth stage of the Software Development Process, it is carried out throughout the previous three stages as well. This is because the process as a whole is iterative. This is helpful as it is much more cost effective to fix problems at the earlier stages of the process.

 

There are 3 different types of Test Data Sets: Normal Data; Extreme Data and Exceptional Data.

Normal Data: This is data that test to see if the program works as expected. For example, in a simple program where the program decides whether a student passes or fails a test, and the pass mark being 50, normal test data would be 72 and 29. The program should display Pass and Fail respectively.

Extreme Data: This type of data set is used to test the boundary’s of the program. So in the Pass/Fail program, the extreme data could be 49, 50,100,101.

Exceptional Data: This data set tests to see if the program can handle unexpected units. So in the Pass/Fail program data such as abc, 100,000, cat, etc..

 

Phases of Testing:

1. Procedure / Module Testing – This is where the individual parts of the code and modules are tested.

2. Integration Testing – This is where the modules are tested to see if they work together.

3. System Testing – The testing of the overall program.

4. Acceptable Testing – This is when the client tests the program to see if it matches up to what they want.

5. Alpha / Beta Testing – This is when the software is sent out for users to test.

 

 

 

 

 

 

 

Debugging with REAL Basic

Firstly to use debugging in REAL Basic you should try to iron out any syntax errors, if any, that your program may have. This is so that the program can begin to run in the first place. Once you have done this, the first port of call would be to create a break point in the code. This easily done by simply clicking the margin o the left of the line of code that you want the code to be broken from. You can then move through the program by stepping through it. This allows you to  view the value that your varibales may be at through each line of code. This is very helpful in making sure that your program does what you want it to and also makes it easy to change.