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()