Computer Fundamentals - Midterm Reviewer (Part 3)

number system

is a way to represent or express numbers. You have heard of various types of number systems such as the whole numbers and the real numbers. But in the context of computers, we define other types of ________.

Binary Number System

In many ways, this system is simpler than the decimal number system because it uses only two characters. The binary number system is used in digital electronics because digital circuits have only two states (two signal levels). Most of the time, 0 and 1 are the two characters used. This is ideal for computer processing because the "1" is used to denote electrical pulse or signal and "0" is used to denote the absence of such signal. The binary notations "0" and "1" are called bits, which is an acronym for BInary digiTs. Often when referring to binary numbers you will hear the terms "LSB" (least significant bit) and "MSB" (most significant bit). These are very much like the terms we use when speaking of decimal numbers. In decimal numbers we refer to the most significant digit (MSD) and the least significant digit (LSD). The LSB is the bit with the least weight. The MSB is the bit with the greatest weight. Normally, binary numbers are shown with the MSB as the leftmost bit.

Decimal Number System

This is the most commonly used number system in the world. It uses ten different characters to show the values of numbers. Because the system uses ten different characters, it is called the base 10 system. The base of a number system tells you how many different characters are used. The mathematical term for the base of a number system is radix. The symbols used are called Arabic numerals consisting of 10 symbols (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). The radix or the base of a decimal system is ten (10).

BCD (Binary Coded Decimal System)

is a method to represent decimal numbers with 4-bit binary words. ___ uses the words from 0000 to 1001 to represent the decimal numbers 0 to 9. It uses 0001 0000 to 1001 1001 to represent decimal numbers 10 to 99. Each decimal digit will be represented using 4-bit binary word.

Zettabyte

is approximately 1,000 Exabytes. There is nothing to compare a _____ to but to say that it would take a whole lot of ones and zeroes to fill it up.

Exabyte

is approximately 1,000 Petabytes. Another way to look at it is that an Exabyte is approximately one quintillion bytes or one billion Gigabytes. There is not much to compare an _____to. It has been said that 5 _____ would be equal to all of the words ever spoken by mankind.

Petabyte

is approximately 1,000 Terabytes or one million Gigabytes. It's hard to visualize what a Petabyte could hold. 1 ______could hold approximately 20 million 4-door filing cabinets full of text. It could hold 500 billion pages of standard printed text. It would take about 500 million floppy disks to store the same amount of data.

Yottabyte

is approximately 1,000 Zettabytes. It would take approximately 11 trillion years to download a Yottabyte file from the Internet using high-power broadband. You can compare it to the World Wide Web as the entire Internet almost takes up about a ____.

Computers understand

machine language only.

ASCII control characters (character code 0-31)

The first 32 characters in the ASCII-table are unprintable control codes and are used to control peripherals such as printers.

Computer codes

are used for internal representation of data in computers. As computers used binary numbers for internal data representation, __________ use binary coding schemes.

Commonly used computer codes are

Binary Coded Decimal System (BCD), American Standard Code for Information Interchange (ASCII), and Extended BCD Interchange Code (EBCDIC).

ASCII printable characters (character code 32-127)

Codes 32-127 are common for all the different variations of the ASCII table, they are called printable characters, represent letters, digits, punctuation marks, and a few miscellaneous symbols. You will find almost every character on your keyboard. Character 127 represents the command DEL.

EBCDIC (Extended BCD Interchange Code)

This is used by IBM and some other mainframe and mini computers and can provide 256 (28 ) different coding arrangements.

Decimal number system

is the most common number system. Other popular number systems include binary number system, octal number system and hexadecimal number system.

The extended ASCII codes (character code 128-255)

There are several different variations of the 8-bit ASCII table. Codes 129-159 contain the Microsoft® Windows Latin-1 extended characters.

Octal Number System

This system is shorthand method for replacing groups of binary digits by single _____ digit to reduce the number of digits required in representing any number. It has a radix or base of eight (8), consisting of 0, 1, 2, 3, 4, 5, 6, 7.

ASCII (American Standard Code for Information Interchange)

This was originally a seven-bit code, which represented 128 (27 ) different characters. However, eight-bit versions (sometimes called ASCII-8), which can represent 256 characters, are now widely used. ASCII is a standardized code first developed for data communications between computers and input/output devices. However, it is used by most microcomputers and minicomputers, as well as by many larger computers. ASCII has been adopted as a standard code by national and international standards organizations.

binary coding

every symbol that appears in the data is represented by a group of bits. The group of bits used to represent a symbol is called a byte. As most modern coding schemes use 8 bits to represent a symbol, the term byte is often used to mean a group of 8 bits.

Kilobyte

is approximately 1,000 Bytes, actually 1,024 Bytes depending on which definition is used. 1 ________would be equal to this paragraph you are reading, whereas 100 _______would equal an entire page.

Megabyte

is approximately 1,000 Kilobytes. In the early days of computing, a _______was considered to be a large amount of data. These days with a 500 Gigabyte hard drive on a computer being common, a ______doesn't seem like much anymore. One of those old 3-1/2 inch floppy disks can hold 1.44 _______or the equivalent of a small book. 100 ________ might hold a couple volumes of Encyclopedias. 600 _______is about the amount of data that will fit on a CD-ROM disk.

Gigabyte

is approximately 1,000 Megabytes. A _______is still a very common term used these days when referring to disk space or drive storage. 1 ______of data is almost twice the amount of data that a CD-ROM can hold. But it's about one thousand times the capacity of a 3-1/2 floppy disk. 1 _____could hold the contents of about 10 yards of books on a shelf. 100 _______could hold the entire library floor of academic journals.

Terabyte

is approximately one trillion bytes, or 1,000 Gigabytes. To put it in some perspective, a ________could hold about 3.6 million 300 Kilobyte images or maybe about 300 hours of good quality video. A _______could hold 1,000 copies of the Encyclopedia Britannica. Ten ________could hold the printed collection of the Library of Congress. That's a lot of data.

Byte

is equal to 8 Bits. A ______can represent 256 states of information, for example, numbers or a combination of numbers and letters. 1 _____could be equal to one character as discussed in ASCII-8 representation. 10 _____ could be equal to a word. 100 ____ would equal an average sentence.

Bit

is the smallest unit of data that a computer uses. It can be used to represent two states of information, such as 1 or 0.

internal circuitry

of a computer needs to represent only binary ones and zeros in its operations. However, several binary based coding systems have been devised to express the machine language instruction codes executed by the CPU and to represent the characters of data processed by the computer. These computer codes make the job of communicating with a computer easier and more efficient. They should be considered as shorthand methods of expressing the binary patterns within a computer.

Hexadecimal Number System

refers to the base 16 number system in which 16 different characters are used, consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.

number system

the technique to represent and work with numbers