<p> ASCII (American Standard Code for Information Interchange)</p><p>ASCII is the most common format for text files in computers and on the Internet. In an</p><p>ASCII file, each alphabetic, numeric, or special character is represented with a 7-bit binary number (a string of seven 0s or 1s). 128 possible characters are defined. </p><p>UNIX and DOS-based operating systems (except for Windows NT) use ASCII for text files. Windows NT uses a newer code, Unicode. IBM's System 390 servers use a proprietary 8-bit code called EBCDIC. Conversion programs allow different operating systems to change a file from one code to another. </p><p>BINARY </p><p>Binary is the base two number system that computers use to represent data. It consists of only two numbers: "0" and "1". In the table below, binary numbers are shown with their decimal equivalents: </p><p>Binary Decimal 0 0 1 1 10 2 11 3 100 4 101 5 110 6 111 7 1000 8 1001 9 1010 10 etc etc</p><p>BIT (BINARY DIGIT) </p><p>A bit is the smallest unit of data in a computer. A bit has a single binary value, either 0 or</p><p>1. Although computers usually provide instructions that can test and manipulate bits, they generally are designed to store data and execute instructions in bit multiples called bytes.</p><p>In most computer systems, there are eight bits in a byte. The value of a bit is usually</p><p>Esen Uzuntiryaki & Özlem Sıla Çakır stored as either above or below a designated level of electrical charge in a single capacitor within a memory device. </p><p>LAB ACTIVITY</p><p>HOW TO READ ASCII DATA?</p><p> From File menu choose Read Ascii Data Fixed Colums</p><p>Click Browse in the Define Fixed Variables dialog box to select the data file.</p><p>For each variable, enter a variable name, the start and end column locations, and a data type.</p><p>Click Add to enter each variable definition.</p><p> From File menu choose Read Ascii Data Freefield</p><p>Click Browse in the Define Freefield Variables dialog box to select the data file.</p><p>For each variable, enter a variable name and data type (numeric or string).</p><p>For string variables, specify the variable width (maximum number of characters).</p><p>Click Add to enter each variable definition.</p><p>For For Fixed </p><p>Freefield Column 1,2,45,a 1 2 45 a 1,1,50,a 1 1 50 a 1,1, 43,a 1 1 43 a 1,2,20,a 1 2 20 a 1,2,35,b 1 2 35 b 1,1,25,b 1 1 25 b 2,1,30,a 2 1 30 a 2,2,15,a 2 2 15 a 2,1,35,a 2 1 35 a 2,2,23,b 2 2 23 b 2,2,48,a 2 2 48 a 2,1,36,a 2 1 36 a</p><p>Esen Uzuntiryaki & Özlem Sıla Çakır</p>