Revision time

•January 10, 2012 • Leave a Comment

3 or 4 hours for computing- I went over what an Alu does and what a cu does, the different types of memory and their speed,measuring the performance, and the speeds of the different types of memory

For info systems I just went over some terms I didnt know

What I’ve learnt this week

•October 31, 2011 • Leave a Comment

To convert binary to decimal you first have to write a number line like so, and then you set put the binary number under the number line, then you add the numbers up so this binary number would be 39

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

To convert decimal to binary you have to still write the number line but you take the decimal number and try to make it fit into diffrent parts of the number like if the number was 27 it could be in binary

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

There are many different units for measuring binary
UNIT. MEAREMENT. STORAGE
Bit. 1 bit. 0 or 1
Byte. 8 bits
Kiliobytes1024bytes. Roughly half a page
Megabyte. 1024kb Small book
Gigabyte. 1024mb. 10 yards of books on a shelf
Terabyte. 1024gb. 300 hours good quality video
Petabyte. 1024tb. 13.3 years of HDTV

We use decimal because we have 10 fingers but a computer uses binary because a computer uses voltages, wether there’s a one or not in the binary number determines if it’s odd or even visa versa if the decimal number is odd it will have a one

R.I.P Steve jobbs

•October 10, 2011 • Leave a Comment

history of video games
In 1952, A.S. Douglas wrote his PhD degree at the University of Cambridge on Human-Computer interraction. Douglas created the first graphical computer game a version of knots and crosses William Higinbotham created the first video game ever in 1958 called Tennis for two In 1962, Steve Russell invented SpaceWar, spacewar was the first game to be used on a computer In 1971, Nolan Bushnell together with Ted Dabney, created the first arcade game. It was called Computer Space based on SpaceWar, in 1971 nolan created pong and a year later founded atari and released pong as a home video game.

What Ive Learnt this week

•September 27, 2011 • Leave a Comment

scripting and Macros

Many programs have macros or a scripting language. Scripts can then be written to execute a number of commands e.g , microsoft word oe filemaker pro. Macros work by recording a series of keypresses which can then be played back as many times as the user wants. Scripts provide the same benefits, but instructions are given in a script or program.

The benefits of script are macros are

  • complex commands can be easily carried out by a single keypress
  • expert users can set up macros/scripts for new users to use
  • more functionality and flexibility can be gained from an application package
  • the user interface can be customised for the user

Procedures produces an effect and a Function produces a value which are both types of a subroutine which is  set of instructions designed to perform a frequently used operation within a program.  A parameter is a value passed within a subroutinw

Documentation

•September 19, 2011 • Leave a Comment

The evaluation stage of the software development proccess is basicly when the client and the developer review the software, maintenance is making changes to the software after it has been handed over to client and enters use

documentation is made to help people understand how to use the software program. the mors common types of documentation are the user guide and the technical guide

The User Guide- Should describe how to use the software there should be tutorial files to take the user through examples of work and enable them to become familiar with the commands but now they more commonly come in electronic form as an online help, which saves money it also allows upgrades

The Technical Guide- This document should say how to install the program, its memory and processor requirements, the version of the software and any help files or system extentsions, it should alos include a troubleshooting section to fix any system problems
Other Types Of Guides:

Extra Functions And Features Guide- normally given with packages which have been upgraded so that familiar users can see directly new aspects of the package

Shortcut Guides- normally pieces of card with shortcuts for the user to access features quickly

Printing Guides-  normally in desktop publishing(DTP) packages to help the user to think about the most appropriate output for their publication

Tutorial Guides- these can be given in either manual or video format users can go through step by step guides to learn how the package works

Testing

•September 19, 2011 • Leave a Comment

(Example program: pass fail 0-49 fail 50-100 pass)

 

Costs from software development differ depending on the project. Analysis,design and testing cost the most with implementation costing less. Testing first takes place at the analysis and design stages with prototypes being made. to save money its generally a good idea to star testing at early stages of the software development process.

The most common types of errors are:

Incorrect interpretation of software specification– which is basicly the client wanting the program to do something    diffrent than what you orignally thought the client wanted

Incomplete logic- Where the program doesnt work properly due something going wrong in the design stage

Not thought of special cases- not thought of specific inputs, like if pass fail program doesnt give correct output when inputs like 0 or 100 is entered

Poor Error handling- it could be if the program suffers a minor error it crashes completly

Bad Time planning- if the program isnt finished by the deadline

Choosing Appropriate test data table sets is important expected output should already be known before testing so this is just checking those predicted outputs are correct

Normal Test Data- should be used first just to make sure the program works as expected

Extreme test data- Is used to test the boundary limits

Exceptionl Test Data- is used to see if the program is robust

What Ive Learnt This Week

•August 29, 2011 • Leave a Comment

this week we were focusing on the first three stages of the software development proccess

– Analysis: is the first stage of the software devolpment proccess its where the analysist reads and understands the problem of the client who wants a program designed for them they also need to interview the client to be clear on what the client needs. they also develop a software specification there is also a legal agreement so they have to develop exactly what the client needs and so neither side decide to back out

-design: is the second stage, a good design makes implementation easier, the design stage breaks the main problem down into more manageable steps this is known as being modular, the aim is to create an algorithm, there are three ways to break down modules, these are step-wise refienment, top-down design and bottom up design there are also three design notations which are flow charts, structure diagrams and pseudocode, the human computer interface is the way which a computer program interacts with the user

-implementation: is the third stage,Implementation is the translation of the design into program code,sequence is were each line of code is executed from t
op to bottom, selection is where only certain lines of code executed, dependent on a decision / branch, iteration is where Lines of code executed repeatedly as in a repeat loop

A finished program should be:

Correct

Maintainable

Reliable

Readable

Portable

Efficient

Robust