Program serial_adc;

{Serial port AD converter circuit control program by Tomi Engdahl}

Uses Crt;

Const
    combase=$2f8;
    MCR=combase+4;
    LCR=combase+3;
    MSR=combase+6;

Procedure Initialize_converter;
Begin
   Port[MCR]:=3;
   Port[LCR]:=0;
End;

Function Read_value:byte;
Var
   value:byte;
   count:byte;
Begin
   value:=0;
   Port[MCR]:=1;
   For count:=0 to 7 Do Begin
      value:=value SHL 1;
      Port[LCR]:=64;
      If (port[MSR] and $10)=$10 Then Inc(value);
      Port[LCR]:=0;
   End;
   Port[MCR]:=3;
   Read_value:=value;
End;

Begin
   Initialize_converter;
   Repeat
      Writeln(Read_value);
   Until KeyPressed;
End.