Application Program
   is concerned with the solution of some problem, using the
   computer as a tool; the focus is on the application, NOT the
   computing system

Systems Program
   is intended to support the operation and use of the computer
   itself, rather than any particular application

Applications Programming 
   development of the software necessary for solving a problem, using
   a computer system

Systems Programming
   development of the software necessary for making a computer system 
   more usable

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   ----------------          ------------         ----------------
  | Program in     |        |            |       |  Program in    | 
  | high-level     |------->|  Compiler  |------>|  machine       |
  | language       |        |            |       |  language      |
  | (source code)  |        |            |       |  (object code) | 
   ----------------          ------------         ----------------

 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    -------------        -------------       ---------------------
   | Program in  |      |  macro      |     | Program in assembly |
   | assembly    |----->|  processor  |---->| language WITH       |--->
   | language    |      |             |     | macro expansions    |
    -------------        -------------       ---------------------
     
       -----------      -------------      ----------      -------------
      |           |    |             |    |          |    | Directly    |  
  --->| assembler |--->| Program in  |--->| linker & |--->| executable  |
      |           |    | object code |    |  loader  |    | memory code |
       -----------      -------------      ----------      -------------
    
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Simplified Instructional Computer (SIC)

   two versions:

       1) Standard model

       2) XE version ("extra equipment")

SIC / XE

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