CHAPTER 8 COMPUTERS As late as the middle 1970’s, the phrase “kick the tires  and  light  the  fires”  was  the  main  theme  in launching an aircraft sortie. This meant that as long as there was an airframe with nothing falling off, an engine that would start and achieve takeoff speed, and air in the tires, the aircraft would be launched. This was  done  so  the  pilots  would  get  their  flight  time every month. Now the mission has become the prime objective of the aircraft. This is not meant to belittle the   importance   of   the   engine   and   airframe. Obviously, they are important, but the aircraft and pilots  are  designated  to  perform  certain  missions.  The performance  of  these  missions  is  dependent  upon  the status  of  the  various  avionics  packages.  If  one  or more of these packages are degraded or not working at all, the aircraft is considered to be partial mission capable  or  not  mission  capable. This lack of mission capability has thrust many an avionics work center supervisor into the spotlight. If you are one of the supervisors who has been there, then you know how  pleasant  the  maintenance  chief  is to  you.  It  is  then  that  you  realize  that  aircraft maintenance is not a game. As we head toward the 21st century, newer and more sophisticated aircraft are being designed and built. The avionics systems are  becoming  more  complex,  thus  allowing  the aircraft   to   perform   more   difficult   missions.   The increased  complexity  forces  the  solutions  to  problems in   microseconds.   The   only   system   capable   of performing these solutions is the computer. In turn, each associated avionics system will act as a sensor that feeds continuously updated information to the computer. The computer processes the data and sends out information to where it is needed. Because  computers  are  used  so  extensively  in Navy  aircraft,  the  avionics  supervisor  must  have  a basic  understanding  and  working  knowledge  of computers. COMPUTER  MAKEUP Learning   Objective:   Identify   computer hardware  and  software. The  electronic  components  of  a  computer  are commonly  called  hardware.  Examples  of  computer hardware   are   cathode-ray   tubes,   transistors, microchips,  printed  circuit  cards,  etc.  Software,  on the other hand, is a term that is applied to a set of computer   programs,   procedures,   and   possibly associated  documentation  concerned  with  the operation  of  a  data  processing  system.  Software includes  compilers,  assemblers,  executional  routines, and  input/output  libraries.  The  advances  in  computer software  provide  the  industry  with  the  greatest  realm of   application   possibilities.   The   problem   of attempting to communicate with a computer has led to the  development  of  symbolic  languages  that  approach human  language.    The fact that a person can tell a computer what to do, just as one directs the actions of another   person,   has   been   made   possible   by   the advances  in  software. Software  is  also  used  to  overcome  design deficiencies  in  computers.  Programming  around design   deficiencies   is   a   common   practice   in   the computer industry. Software is, in fact, often used to determine   design   feasibility.   The   practice   of designing a computer with a computer is a common practice  of  design  engineers. Perhaps the best software application has been in the  area  of  real-time  processing.  Real-time processing  is  a  situation  where  the  data  is  submitted  to a computer, and an immediate response is obtained. The  capability  of  a  computer  to  perform  real-time processing could determine the success or failure of an  aircraft’s  mission. Programming in a universal language has led to the  development  and  refinement  of  a  number  of computer  languages.  Many  of  these  languages  are  for a special area or purpose. For example, FORTRAN (FORmula  Translator)  for  business  and  scientific programs,   COBOL   (COmmon   Business   Oriented Language)  for  business,  and  Jovial  for  large  scale, computer-based,  command  and  control  systems. PL/1 (Programming Language/one) is a language for real-time   systems.    Each of the languages fulfills a specific  need  for  a  specific  problem,  but  lacks  the universal  ideal  application. 8-1