Uses crt, dos;

Label Finish, ll00;

Const
  baud = 38400;
  COM=$3F8 { $2F8 };
  intr=$0C { $0B };

Var
  stv, srv : pointer;
  cnt : word;
  b : byte;
  key : char;
  speed_fr : word;

{----------------------------------------------------------------------------------}
{$F+}
Procedure int_1c; interrupt;
  Begin
    inc(cnt);
    if cnt=18 then begin cnt:=0; write ('g') end;
  End;
{$F-}
{-----------------------------------------------------------------------------------}
{$F+}
Procedure int_rs; interrupt;
  Begin
    b:=port[COM];
    write (b,' ');
  End;
{$F-}
{----------------------------------------------------------------------------------}

BEGIN
  speed_fr:=trunc(115200/baud+0.5);
  port[COM+3]:=$80; { ўЄ«. гбв ­®ўЄ бЄ®p®бвЁ }
  port[COM+1]:=hi(speed_fr); port[COM+0]:=lo(speed_fr);
  port[COM+3]:=$00; { 5 bit, 1 stop, parity=none }
  port[COM+4]:=0;
  port[COM+2]:=$03; { FIFO on }
  port[COM+1]:=$01; { interrupt when rec'd data is available }

  getintvec($1C,stv);
  getintvec(intr,srv);

  cnt:=0;
  setintvec($1C,addr(int_1c));
  setintvec(intr,addr(int_rs));

ll00 :
  if keypressed then begin
    key:=readkey;
    goto Finish;
  end;

{  b:=port[COM+5]; }
{  if (b and $01)<>0 then begin }
{    b:=port[COM]; }
{    write (b,' '); }
{  end; }

  goto ll00;

Finish :
  setintvec($1C,stv);
  setintvec(intr,srv);
  halt;
END.