Program On_Interval_Gosub;

{$I wrtvram.inc }
{$I time.inc }
{$I interrup.inc }

Procedure PrintTime(Column,Row:Byte);
 Var time :String[8];
 Begin
  Time := GetTime;
  WriteVram(0,column+Row*80,Addr(Time[1]),8);
 End;

Procedure InterruptServiceRoutine;
 Begin
  PrintTime(26,10);
  Inline($f3);
 End;

Begin

  SetInterrupt(Addr(InterruptServiceRoutine),50);

  ClrScr;
  Writeln('**** Testing interrupt service routine **** ');
  Writeln;
  Writeln('Hooked $0038 interrupt by Kari  Lammassaari.');
  Writeln;
  Writeln('      Input prevents DOS-interrupt ! ');
  GotoXY(1,11); Write('Interrupt driven time =>');
  GotoXY(1,14); Write('Press a key to exit ! ');

  Repeat
    {This is the program loop . }
  Until KeyPressed;

  RemoveInterrupt;  { DON'T FORGET THIS ! }
End.