NAME
    AllocTrap -- allocate a processor trap vector

SYNOPSIS
    trapNum = AllocTrap(trapNum)
    D0                  D0

    LONG AllocTrap(LONG);

FUNCTION
    Allocate a trap number from the current task's pool.  These trap
    numbers are those associated with the 68000 TRAP type instructions.
    Either a particular number, or the next free number may be
    allocated.

    If the trap is already in use (or no free traps are available) a -1
    is returned.

    This function only affects the currently running task.

    Traps are sent to the trap handler pointed at by tc_TrapCode.
    Unless changed by user code, this points to a standard trap
    handler.  The stack frame of the exception handler will be:

            0(SP) = Exception vector number.  This will be in the
                    range of 32 to 47 (corresponding to the
                    Trap #1...Trap #15 instructions).
            4(SP) = 68000/68010/68020/68030, etc. exception frame

    tc_TrapData is not used.


WARNING
    Traps may not be allocated or freed from exception handling code.
    You are not allowed to write to the exception table yourself.  In
    fact, on some machines you will have trouble finding it - the VBR
    register may be used to remap its location.

INPUTS
    trapNum - the desired trap number {of 0..15} or -1
              for no preference.

RESULTS
    trapNum - the trap number allocated {of 0..15}.  If no traps are
              available, this function returns -1.  Instructions of the
              form "Trap #trapNum" will be sent to the task's trap
              handler.

SEE ALSO
    freetrap