CHAPTER 1 Flashcards
Types of Prefix
- Binary & Dinary
What is BITS
- Value either 1 or 0
What is NIBBLE
- 4 Bits
What is BYTE
- 8 Bits
Why use binary > Denary
- More Accurate
Binary System
- 1 & 0 only
- Base 2 System
What is Range
- The Smallest and Largest number that can be represented in a given bit size
- 0001 & 1111 = 1 to 15 is the range
One Complement
- Invert all of 1 and 0 values ( Terbalikkan )
- 1010 to 0101
How to One Compliment
- If the values is positive , directly changed to binary
- If the values is negative , convert to positive then do one compliment
What is the used of Two Compliment System
- Represent positive or negative integer
- Carry out substraction by addition
Most Significant Bits
- the value on the left ( Last )
Less Significant Bits
- the value on the right ( First )
When Overflow happened
- When the result of addition is larger than the given bit size
- When largest number that counter can hold is exceeded
Can overflow be avoided ?
- No
How to detect overflow occured ?
- When carry in and carry out on MSB is not the same
What is word size ?
- Number of bit it can handle
What is the uses of hexadecimal numbers ?
- To define locations in memory
- To define colour on web pages
- To represent MAC Addresses
- To display error message
Why use hexadecimal in computers ?
- Easier to use
- Readable
- More compact
What types of Binary Coded Decimal ( BCD )
- Packed BCD
- Unpacked BCD
What is Packed BCD ?
- Each number is encoded into 4 bits
- 8 = 1000
What is Unpacked BCD ?
- Each number is encoded into 1 byte
- 8 = 00001000
Uses of BCD
- BIOS store date and time , easy to be converted to ASCII for display
- Early model of PS3 to store date and time
Applications of BCD
- BIOS store date and time in BCD format
- Represent currency values
Disadvantages of BCD
- Difficult to perform arimethic operations
- Longer than true binary
- Required more storage space
ASCII CODE
- Consist of 7-bits
- ## Each character has its own unique character code
What is Sampling ?
- The amplitude of sound wave taken at different point of time
- Taking measurment at regular interval and store it
What is bit depth ?
- The number of bits assigned to each sample
What is sampling rate ?
- The number of sample taken per unit time
What is analogue data ?
- Data obtained by measurement of a physical property
- Continous range of values
What is digital data ?
- Data that has been stored in a binary value
- Discrete range of values
What is sampling resolution ?
- The number of bits used to store each sample
What is Analogue to Digital Converter ( ADC ) ?
- Convert analogue sound to digital signal to be stored in computer
What is Digital to Analogue Converter ( DAC) ?
- Convert digital signal stored to analogue sound so that can be played on a device such as speaker
How ADC works?
- Measure Amplitude at regular time interval
- Sample are recorded as binary numbers
What is bandwith ?
- The ability of recorded signal to be reproduce at any degrees of resolution
- Rate of data to be transmitted over a network or connection
Factor Affecting digital audio
- Sampling rate/frequancy
- Sampling resolution/bit depth
- Recording Channel
What is compression ?
- Tool for reducing file sizes
What happened when compressing ?
- The data will be removed
Type of compression ?
- Lossy and loseless
Method Of lossy compressison
- JPEG
- MP3
Method of loseless compression
- Zip
- RLE
What is lossless compression ?
- When being compressed , quality remain the same
- File can be restored to its original state
- Allow data to be perfectly reconstruct
What is lossy compression ?
- Permanently remove data
- Reduce size and quality
- Original bit depth is reduced
What is RUN-LENGTH ENCODING (RLE)
- Compress a number of different file format
- Lossless
- Only affective when theres a long run of repeated
Presentation of RLE
- First Value : number of identical data
- Second : Code of data ( ASCII )
How bitmapped image encoded ?
- Made of pixels
- Each pixels has one colour
- Each colour has unique binary coded
- Code for each colour is stored in sequence
Type of Graphic images
- Bitmap ( Pixels )
- Vector
Pixels ( Picture element )
- Smallest possible address area define by a solid colour
- Represented as binary , in an images
Bitmap images
- Images are stored as a series of pixels
What does file header contain ?
- File size
- Dimension of images
- Colour depth
- Type of compression
Screen resolution
- How many pixels can your screen display vertically and horizontolly
Image resolution
- Measurement of Dot per inch ( DPI )
Resolution
- Number of pixels in an image
Colour depth
in black and white pic , only 2 colour needed , so colour depth of 1 bit
- Measured in bits
- The bits indicated how many colour available for each pixel
Number of bits for
- ASCII
- Extended ASCII
- UNICODE
- 7
- 8
- 16/32
Impact of changing sampling resolution
- Bits used higher
- More amplitude can be presented
- The digital soundwave is closer to original analogue wave
- Reduce quantisation error
How sound is represented ?
- The amplitude is recorded
- The amplitude is given corresponding
binary value - Each amplitude is stored in sequence
What happen when sampling rate increased ?
- Small gap
- Less Quantisation error
- Digital wave form closer to Analogue Wave form
What happen when Sampling resolution increased ?
- More bits per sample
- ## Less Quantisation error
Property
- Data about the shape
Example of property
- Black Line
- Black fill
- White fill
- Font of letter
Drawing list
- List of command to draw each object
