FIVE-PIN  CONNECTOR—  A connector that has five pins,  usually  used  to  connect  a  keyboard  to  the CPU. FORTRAN (FORmula TRANslator)— A high--level programming    language mathematical applications. H for   scientific   and HARD-SECTORED—   Wedge-shaped    storage division on a floppy disk from time of manufacture. HIERARCHICAL  DIRECTORY—   A term used to refer to the organizational method of arranging files either  in  a  DOS  tree  structure  or  in  the  file-and- folder method. HUB— The center part of the tape reel that attaches to the tape drive. HYPERTEXT—  A  document  retrieval  network  having till-text files and dynamic indexes for links among documents. HYPOTHERMAGRAPH—   A  piece  of  equipment that is used to record the temperature and humidity in a computer room. I INSTRUCTION  AND  CONTROL—  The portion of the control section that includes the combinational and sequential circuits that make up the decision- making and memory-type functions. INTEGRATED  CIRCUIT—  A miniaturized chip in which  semiconductor  components  and  other  such technology combine the functions of a number of conventional   components   (such   as   transistors, resistors, capacitors, and diodes). INTERNAL  DIAGNOSTICS—  Diagnostics that are run when the computer is started. IPL  (Initial  Program  Load  )— A set of instructions that cause other instructions (the operating system) to be loaded into the main memory of the computer. This must be done each time the computer is turned on. L LETTER-QUALITY   MODE—   The  mode  that produces   high--quality   printed   output   from   a printer. LIBRARIAN—  Person  responsible  for  the  safekeeping of all computer files, such as diskettes, disk packs, and magnetic tapes. LOCAL-AREA   NETWORK—   A  network  that normally   operates   within   a   well-defined   and generally  self-enclosed  area.  The  communication stations or terminals are linked by cable. M MAGNETIC CORE STORAGE— System of storage in  which  data  is  represented  in  binary  form  by means of directional flow of magnetic fields in tiny, doughnut-shaped arrays of magnetic cores. MAGNETIC DOMAINS— The data that is stored by changing   the   polarity   of   the   magnetized   dots (bubbles). MAINFRAME COMPUTERS— This term is usually used  to  designate  large-scale  computer  systems, although the precise definition of mainframe is the cpu  and  the  control  elements  of  any  computer system. MATRIX—   Orderly  array  of  symbols  by  rows  and columns. MINICOMPUTERS—  Midsize  computers  that  are smaller than large-scale systems but with the same components.  They  are  less  expensive  and  have  less strict environmental requirements. MODEM—  A device that converts data from digital to analog   format   for   transmission   on   analog transmission  lines,  and  also  converts  data  in  analog format to digital format for computer processing. MULTIPLE-FILE  DIRECTORIES—  An option of the  operating  system  that  allows  for  several  files  to be contained in a directory. J N JULIAN  DATE—  Form  of  calendar  representation within a computer system, indicating the year and the number of elapsed days in the year. NONVOLATILE STORAGE— Storage medium that retains its data in the absence of power. AI-2