Comp Sci 1BA3 Test #1 Review

Comp Sci 1BA3 Test #1 Review - Computer Science 1BA3...

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Computer Science 1BA3 Midterm Review Chapter Two Representing Digital Data (Page 55-58) Binary Numbering System: The numbering system that represents all numbers using just two symbols (0 and 1). Byte: 8 bits Kilobyte (KB): 1000 bites Megabyte (MB): 1 million bytes Gigabyte (GB): 1 billion bytes Terabyte (TB): 1 trillion bytes All data must be converted into bits before computer can store or process it As the computer processes only bit operations (as directed by the programs), the interpretation of a string of bits as numbers, words and other information is done by the software ASCII (American Data Standard Code for Information Interchange): coding system traditionally used with PCs Unicode: A coding system for text-based data using any written language Unicode is a universal coding system designed to read any written language 16-bit code providing 65,536 characters and symbols EBCDIC: A fixed-length, binary coding system widely used to represent text-based data on IBM Representing Numbers 1. We have ASCII codes for digits, so represent numbers as strings of ASCII characters 2. Text may be practical for representing symbolic data that are number strings such as student I.D. numbers or phone numbers (arithmetic operations not required) 3. In general it is not practical to store numeric values (arithmetic required) as strings of characters 4. Largest number that can be represented by two bytes using ASCII codes = 99 Place value of decimal number system The Binary Number System To convert decimal data that humans use, into binary number system. The binary number system works the same way as the decimal system, but has only two available symbols (0 and 1) rather than ten (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9). A string of bits can be used to represent a sub-set of integers in several different ways: If only positive integers are represented the range can be 0 to 65,535 If both negative and positive integers (signed integers ) are to be represented: the bit patterns must encode the sign as well as the magnitude of the integers
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There are several methods when using 16 bits, the range of integers -32768 to +32767 can be represented. Using 32 or 64 bits can increase the range of integers that can be represented Conversion of Binary to Decimal Representing Real Numbers (Page 56-57) Graphics Data (Page 58-59) How Are Images Represented? o Made up of tiny dots called pixels o A pixel: the smallest part of an image; A number representing the colour in the image o Image is split up into columns and rows and the pixels take up all of them o Example: An image could have 60,000 pixels; if an image is just Black and White, it's called a binary image. o
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Comp Sci 1BA3 Test #1 Review - Computer Science 1BA3...

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