Title: How to read a byte from the parallel port?
Question: How to read a byte from the parallel port?
Answer:
value:=port[$379]; { read from port }
and
port[$379]:=value; { write to port }
Var
BytesRead : BYTE;
begin
asm { Read port (LPT1) via Inline asm }
MOV dx,$379;
IN al,dx;
MOV BytesRead,al;
end;
BytesRead:=(BytesRead OR $07); { OR and then XOR the data }
BytesRead:=(BytesRead XOR $80); { to mask the unused bits }