Int 21 Fn D1  - Novell Netware - Synchronization Services - Lock Logical   [N]

   AH = D1h
   AL = lock type (00h exclusive, 01h shareable)
   if function C6h lock mode 00h:
       DL = mode (00h no wait, 01h wait)
   if function C6h lock mode 01h: (Novell only)
       BP = lock timeout in timer ticks (1/18 sec), 0000h no wait

Return: AL = status (see #1498)
Desc:  attempt to lock all logical record names listed in the log table

Notes: this function is supported by NetWare 4.6+, Advanced NetWare 1.0+,
     Banyan VINES, and Alloy NTNX
   status FFh will be returned if one or more logical records have been
     exclusively locked by another process
   locks on logical record names are advisory and may be ignored by other
     applications

See Also: AH=C2h,AH=CBh,AH=D0h,AH=D3h,AH=D5h