Source code in the action! programming language

PROC Wait(BYTE frames)
  BYTE RTCLOK=$14
  frames==+RTCLOK
  WHILE frames#RTCLOK DO OD
RETURN

PROC Main()
  DEFINE PTR="CARD"
  PTR ARRAY num(12),obj(12)
  BYTE i,j

  num(0)="first" num(1)="second" num(2)="third"
  num(3)="fourth" num(4)="fifth" num(5)="sixth"
  num(6)="seventh" num(7)="eight" num(8)="ninth"
  num(9)="tenth" num(10)="eleventh" num(11)="Twelfth"

  obj(0)="And a partridge in a pear tree."
  obj(1)="Two turtle doves"
  obj(2)="Three french hens"
  obj(3)="Four calling birds"
  obj(4)="Five golden rings"
  obj(5)="Six geese a-laying"
  obj(6)="Seven swans a-swimming"
  obj(7)="Eight maids a-milking"
  obj(8)="Nine ladies dancing"
  obj(9)="Ten lords a-leaping"
  obj(10)="Eleven pipers piping"
  obj(11)="Twelve drummers drumming"

  FOR i=0 TO 11
  DO
    PrintF("On the %S day of Christmas,%E",num(i))
    PrintE("My true love gave to me:")
    IF i=0 THEN
      PrintE("A partridge in a pear tree.")
    ELSE
      j=i+1
      WHILE j>0
      DO
        j==-1
        PrintE(obj(j))
      OD
    FI
    PutE()
    Wait(50)
  OD
RETURN