INT 15 - MultiDOS Plus - REQUEST RESOURCE SEMAPHORE BY NAME
        AH = 1Bh
        DS:SI -> 8-byte name
Return: AH = status
            00h successful
            02h invalid semaphore number
            03h caller already owns semaphore
            04h out of string space
Notes:  (see AH=01h"MultiDOS")
        equivalent to AH=1Ah followed by AH=01h
SeeAlso: AH=1Ah"MultiDOS",AH=1Ch"MultiDOS",AH=1Dh"MultiDOS"