INT 15 - MultiDOS Plus - REQUEST RESOURCE SEMAPHORE                             
	AH = 01h
	AL = semaphore number (00h-3Fh)
Return: AH = status
	    00h successful
	    02h invalid semaphore number
Notes:	if the semaphore is not owned, ownership is assigned to the calling
	  task and the call returns immediately
	if the semaphore is already owned by another task, the calling task
	  is placed on a queue for the semaphore and suspended until it can
	  become owner of the semaphore
	semaphore 0 is used internally by MultiDOS to synchronize DOS access
SeeAlso: AH=02h"MultiDOS",AH=10h"MultiDOS",AH=1Bh"MultiDOS"