INT 21 - Novell NetWare - GET NETWORK SERIAL NUMBER
        AH = E3h subfn 12h
        AL = 00h
        BX = CX = DX = 0000h
        DS:SI -> request buffer (see below)
        ES:DI -> reply buffer (see below)
Return: AL = status
            00h successful
Desc:   return the serial number and application number for the software
          installed on the file server
Notes:  this function is supported by Advanced NetWare 2.1+
        reportedly, the workstation crashes if AL,BX,CX, and DX are not all
          zero
SeeAlso: AH=E3h/SF=0Ch,AH=E3h/SF=11h

Format of request buffer:
offset   size   description
 00h     WORD   0001h (length of following data)
 02h     BYTE   12h (subfunction "Get Serial Number")

Format of reply buffer:
offset   size   description
 00h     WORD   (call) 0006h (size of following results buffer)
 02h   4 BYTEs  (big-endian) NetWare server serial number
 06h   2 BYTEs  (big-endian) NetWare application serial number

.