function TestPrinterStatus(LPTPort: Word): Byte;
var
 Status: byte;
 CheckLPT: word;
begin
 Status := 0;
 if (LPTPort >= 1) and (LPTPort <= 3) then
 begin
  CheckLPT := LPTPort - 1;
  asm
  mov dx, CheckLPT;
  mov al, 0;
  mov ah, 2;
  int 17h;
  mov &Status, ah;
  end;
 end;
 Result := Status;
end;

{
 Pass in the LPT port number you want to check & get the following back:
 01h - Timeout
 08h - I/O Error
 10h - Printer selected
 20h - Out of paper
 40h - Printer acknowledgement
 80h - Printer not busy (0 if busy)
 Note:
 This function doesn't work under NT, it gives an access violation
 from the DOS interrupt call.
}