INT 21 - LANtastic v4.1+ - SET AUTO-LOGIN DEFAULTS
AX = 5FB6h
ES:DI -> pointer to ASCIZ default user name, immediately followed by
ASCIZ password
BL = adapter number to use for default login attempt
FFh try all valid adapters
00h-05h try adapter 0-5 explicitly
Return: CF clear if successful
CF set on error
AX = error code
Notes:  call with ES:DI -> two nulls to disable auto-login

See also: 215FB7

215FB6 - LANtastic v4.1+ - SET AUTO-LOGIN DEFAULTS