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                        PERIYODA
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PERIYODA - Periodic Function Movies, ver.2.0, 1991
Z. Juricskay, Cs. Markus, P. Pacher, G. Mark
Physical Institute of the Technical University
H-1111 Budapest, Budafoki u.8. Hungary


     This  program  is  an  aid  for  making  and  re-playing 
"movies"   that   demonstrate   physical   and   mathematical 
models.

     There are many physical processes that can be  described 
by simple formulas which present nearly exact pictures of the 
real world, for example, two-dimensional waves.

     Using PERIYODA anyone can design  two  dimensional  time
dependent (periodic) - F(x,y,t) - functions and display  them 
in  films.  These  films  are  about  two  or  three  seconds  
long  and  they  are  even  close  to TV-quality in speed!

     Possible educational uses:

  -  It can show the process  of  occurences  that  can't  be 
     shown easily.
  -  In physics there are problems that can't be demonstrated 
     any other way.
  -  Certain aperiodical phenomena can also be  demonstrated.
  -  It can  demonstrate  which  parts  of  the  mathematical 
     model are identical with reality  and  which  parts  are  
     different. 
  -  In mathematics: It can teach two-dimensional  functions, 
     the meaning of parameters, ...
  -  After an exam it can demonstrate incorrect solutions, so 
     anyone can see the problems with that. It is much better 
     than the well-known red ink.

     Experiments can be planned, films can be made before the 
lesson, so logical scenes need not be interrupted by changing 
equipment. The students can make their own movies using their 
own functions so they can solve their  problems  without  any 
help.  It  can  be  an  example  for  learning-as-a-game   in 
mathematics!

     There are several options that can be changed:

  -  the function
  -  minimum and maximum value of the x, y parameter
  -  the step of the x, y parameters
  -  the time step
  -  the axonometry
  -  the number of the phases - in our opinion it must be  at 
     least 20-30 to create a nice "movie"
  -  the indicator of the time that can be a  clock  or  just 
     the number of the actual phase

     Using the menu is easy: the movement of the MOUSE or the 
 UP   and  DOWN   keys move the highlighted bar; the    ENTER   
key or the left button on the MOUSE  chooses  the  menu-point 
which can give a new menu;  the    ESC    key  or  the  right 
button of the MOUSE forces the  program  to  leave  that  new 
menu; and the   F1   button activates the HELP  anywhere.  To 
leave the program, choose QUIT in the FILE-MENU or just press 
  ALT   and   X   together.

     Watching a film you can use  UP  and  DOWN  key to  slow
down or quick up re-playing and  ESC  to leave  this  option.
Editing a text  LEFT , RIGHT , INSERT , HOME , END  functions
are available. To accept the string just press ENTER  and  to       
go back to last point press the  ESC  button.

     The  DIRECTORY  function is really easy-to-use:  LEFT  ,
RIGHT , PGUP , PGDN , HOME  and  END  functions help  you  to
find the file you are intrested in.      

     Starting the program the user can see the screen divided 
into three parts: 

  -  the main part (and the biggest one) is the movie-window: 
     film creation and re-playing take place here.  There  is 
     a polygon showing  the  axonometry   and  a  short  line 
     delineating  the  height  of  the  function-interval  in 
     points.
  -  the menus that are on the left side of the screen.
  -  the icons showing the options of our new film.

     Icons demonstrate the minimum and maximum value  of  the 
two variable (x and y), the minimum value and the  period  of 
the time, the number and the indicator of the phases.

     Any kind of inscription can be changed  easily,  because 
they can be found - with the EGA  and  VGA  colours  and  the 
whole structure of the MENU - in different files attached  to 
the program.

    PERIDEMO is a restricted version of PERIYODA, only the LOAD, 
PLAY, PLAY-FROM-MEMORY  and  -  of  course  -  QUIT  work  as 
described; other menupoints give their HELP by choosing them.

    System requirements:
      
      Þ    IBM PC, XT, AT or compatible computer
      Þ    at least 640 Kbyte RAM memory
      Þ    CGA, EGA (or VGA) or HERCULES graphics card
      Þ    a floppy drive or a hard disc
      Þ    if possible: MICROSOFT or compatible MOUSE
    
    PERIYODA and the DEMO version is made by:
           
           Zolt n Juricskay   &   Csaba M rkus

           P‚cs,                  S rv r,
           Olga u. 13.            Szatm r u. 4.
           H-7632                 H-9600
           HUNGARY                HUNGARY

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