Skip to content

    ReadPortB

    Read bytes from a PC port.

    Declaration

    Source position: x86.pp line 30

    function ReadPortB(Port: LongInt) : Byte;

    procedure ReadPortB(Port: LongInt; var Buf; Count: LongInt);

    Description

    The procedural form of ReadPortB reads Count bytes from port Port and stores them in Buf. There must be enough memory allocated at Buf to store Count bytes.

    The functional form of ReadPortB reads 1 byte from port B and returns the byte that was read.

    Note that you need permission to read a port. This permission can be set by the root user with the FpIOPerm call.

    Errors

    In case of an error (not enough permissions read this port), runtime 216 (Access Violation) will occur.

    See also

    Name Description
    FpIOPerm Set permission on IO ports.
    ReadPort Read data from a PC port.
    ReadPortW Read Words from a PC port.
    ReadPortL Read longints from a PC port.
    WritePort Write data to PC port.
    WritePortB Write byte to PC port.
    WritePortL Write longint to PC port.
    WritePortW Write Word to PC port.