Data representation
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The document discusses data representation in computers. It explains that: 1) Data is stored in binary form using bits, with the basic unit being a byte made up of 8 bits. Each byte can represent one character using ASCII codes. 2) When a user types a letter on a keyboard, it is converted to its ASCII binary code and stored in memory. This allows the letter to be processed and displayed on an output device. 3) Common units for measuring data size are kilobytes, megabytes, and gigabytes which are powers of 1024, 1024^2, and 1024^3 bytes respectively. Clock speed of a processor, measured in Hertz, determines how fast it can process data.
Data representation
- 1. DATA REPRESENTATIONBinary Number SystemBitByteCharacterASCII
- 2. BINARY DIGITBit is smallest unit of data
- 4. 4Binary Communication Between Hardware and Software
- 5. Step 1.The user presses the capital letter D (shift+D key) on the keyboard.Step 4.After processing, the binary code for the capital letter D is converted to an image, and displayed on the output device.How is a letter converted to binary form and back?Step 2.An electronic signal for the capital letter D is sent to the system unit.Step 3.The signal for the capital letter D is converted to its ASCII binary code (01000100) and is stored in memory for processing.
- 6. BITBIT stands for Binary DigitIt is the smallest size of computer data storageIt can either store a binary “0” or a “1”01ORTherefore a BIT can have 2 different values or combinations.
- 7. Byte – a group of 8 bits. Therefore, a byte can represent up to 28=256 values.The values can range from 0 to 255 or from -128 to 127.The fundamental data unit of a computer.????????
- 8. Data Representation 2 Presentation Unit 2Slide 8BYTEThe 256 possible combinations are shown below:
- 9. Data Representation9Bytes as unsigned integersBase 2 number using positional notation00100011128 64 32 16 8 4 2 1mostsignificantbitleastsignificantbitValue is 32 + 2 + 1 = 3310
- 10. CHARACTER8 bits = 1 byte = 1 character (like ‘A’)One byte represent one character such as A, 7, 9 and @For example the 01000110 represented a letter “F”01000110=F
- 11. ASCII
- 12. Example ‘a’ = 11000012
- 13. ============Binary010010000110010101101100011011000110111100101100001000000111011101100111011100100110110001100100Decimal721011081081114432119103114108100Hello,world============Note: 12 characters – requires 12 bytesEach character requires 1 byte“Hello, world” Example
- 14. DATA MEASUREMENT1 KB = 210 bytes = 1024 1 MB = 220 bytes = 1048576 byte1 GB = 230 bytes = 10737418241 TB = 240 bytes =1099511627776
- 15. CLOCK SPEED MEASUREMENT“SPEED” means how fast it can process dataEvery processor contains a system clock. The system clock control the speed of all operations within a computer.The clock speed unit is measured in Hertz.A Hertz is one cycle per second.
- 16. UNIT OF SPEED