Dim A$(22)
A$(0)=" Desk "
A$(1)="  About GFA BASIC  "
A$(2)="-------------------"
A$(3)="1"
A$(4)="2"
A$(5)="3"
A$(6)="4"
A$(7)="5"
A$(8)="6"
A$(9)=""
A$(10)=" Options "
A$(11)="  Cosine  "
A$(12)="  Fill    "
A$(13)="  Swiggle "
A$(14)="----------"
A$(15)="  Quit  "
A$(16)=""
A$(17)=" Rectangles "
A$(18)="  GFA       "
A$(19)="  Boxes     "
A$(20)=""
A$(21)=""
Menu A$()
Menu Off
On Menu  Gosub Info
Do
  On Menu
Loop
Procedure Info
  Menu Off
  Cls
  Value=Menu(0)
  If Value=1
    Alert 2,"GFA BASIC DEMO|Tim Purves|MichTron",1,"  OK  ",B
  Endif
  If Value=11
    Gosub Cosine
  Endif
  If Value=12
    Gosub Fill
  Endif
  If Value=13
    Gosub Lisa
  Endif
  If Value=15
    End
  Endif
  If Value=18
    Gosub Rect2
  Endif
  If Value=19
    Gosub Rect1
  Endif
  Cls
  Menu A$()
Return
Procedure Cosine
  Q=1.2
  P=0.03
  Target=Timer+2000
  Repeat
    For F=0 To 4
      Color F
      I=I+P
      S=Sin(I)+1
      C=Cos(I*Q)+1
      Line 320*S,100*C,640-320*C,100*S
    Next F
  Until Timer>Target
Return
Procedure Fill
  Ellipse 320,200,320,200,-7200,0
  Print "Click on Area to fill"
  Target=Timer+2000
  Repeat
    I=(I+1) Mod 36
    Deffill Random(3)+1,3+(I<24),I Mod 24+1
    Repeat
    Until Mousek
    Fill Mousex,Mousey
  Until Timer>Target
Return
Procedure Rect1
  Graphmode 3
  Target=Timer+2000
  Repeat
    Box I Mod 640,I Mod 200,639-I Mod 640,199-I Mod 200
    Add I,8
  Until Timer>Target
Return
Procedure Rect2
  Deftext 2,16,,32
  Text 200,50,"GfA BASIC Interpreter"
  Deftext 3,4,,13
  Text 200,80,"Distributed by GFA Data Media (UK) Ltd"
  Graphmode 3
  Target=Timer+2000
  Repeat
    For A=3 To 99
      For I=0 To 150 Step A
        Pbox I,I,I+A,I+A
      Next I
    Next A
    For A=99 Downto 3
      For I=0 To 150 Step A
        Pbox I,I,I+A,I+A
      Next I
    Next A
  Until Timer>Target
Return
Procedure Lisa
  ' Lissa
  ' P und Q variieren
  Q=3/4
  P=0.1
  Color 2
  Plot 320,199
  I=0
  Target=Timer+2000
  Repeat
    I=I+P
    S=Sin(I)+1
    C=Cos(I*Q)+1
    Draw  To 320*S,100*C
  Until Timer>Target
Return