Int 21 Fn C500  - Novell Netware - Synchronization Services - Open Semaph  [N]

   AX = C500h
   DS:DX -> semaphore name (counted string, max 127 bytes)
   CL = initial value for semaphore

Return: AL = status
       00h successful
       BL = number of processes having semaphore open
       CX:DX = semaphore handle
       03h name length greater than 127
       (refer to Novell document FYI.A.4611)
       FEh invalid name length
       FFh invalid semaphore value

Notes: this function is supported by NetWare 4.6+, Advanced NetWare 1.0+, and
     Alloy NTNX
   the semaphore's value is incremented by AX=C503h and decremented by
     AX=C502h

See Also: AX=C501h,AX=C502h,AX=C503h,AX=C504h,AX=F220h/SF=00h