Tidy Up!

UNICODE - 16 bit, capable of storing more characters allows it to store more languages



Advantages and Disadvantages of Binary

+ Easier to store the two states on backing storage
- its harder to write programs in Binary (longer, difficult to spot mistakes)
+ not affected by voltage degredation
+ fewer rules of addition to code into the processor (0 + 0, 0 + 1, 1 + 0, 1 + 1)

Calculation of Graphics Sizes

How do we do it!?


= length in pixels * height in pixels

= (length * dpi) * (height * dpi) dpi = resolution


DPI = Dots per inch

Bitmaps

How are graphics stored in a computer system - bitmap!

stores the (0,1) colour of every individual pixel

Resolution (High res has more pixels)

We measure resolution - Dots Per Inch (DPI)

Binary

Sizes

Bit
Byte
Kilobyte
Megabyte
Gigabyte
Terabyte

Bit and get it to Megabyte
/8 = byte /1024 = kilobyte /1024 = megabyte

Terabyte to kilobyte
Terabyte * 1024 = gigabyte * 1024 = Megabyte * 1024 = Kilobyte

ASCII Code and FPR!

ASCII stands for?

American Standard Code for Information Interchange


How many bit code is it?

7, extended ASCII uses 8

How many characters can it represent?

128

What is the Character Set?

All the characters that can be represented (text, numbers, punctuation, includes control characters)

What are the control Characters?

Space, Tab, Enter ... Non Printable Characters that change the format of display

Floating Point Representation is used to represent Real Numbers.

How do Computers use Floating Point to represent Real Numbers?


By using a MANTISSA and an EXPONENT - Mantissa represents the actual number. Exponent tells us how many places to move or "float" the decimal point!

Binary Numbering System

The Binary Numbering System is a two state numbering system using 0 and 1 as its two states

The Computer System is a two state machine using ON and OFF as its two states.

The ON and OFF states can be represented by the 1 and 0

Finishing the SDP!

Evaluation Stage

These are the features we evaluate software
Readability - blank lines, indentation, good variable names and internal commentary (pseudocode)
User Interface - how easy it is to use, how it looks
Fitness For Purpose - does what the porogram is supposed to do

Maintenance
Perfective - add in new features
Adaptive - changing the program to work on different platforms
Corrective - fixes any errors not found at testing