INT 21 - Novell NetWare 4.0, Alloy NTNX - LOG/LOCK PERSONAL FILE (FCB)
AH = CAh
DS:DX -> FCB (see AH=0Fh)
if function C6h lock mode 01h:
AL = log and lock flag
00h log file only
01h lock as well as log file
BP = lock timeout in timer ticks (1/18 sec)
Return: AL = error code
00h successful
96h no dynamic memory for file
FEh timeout
FFh failed

See also: 21CB

21CA - Novell NetWare 4.0, Alloy NTNX - LOG/LOCK PERSONAL FILE (FCB)