Int 6A Fn D0  - Decnet Dos Local Area Transport - Open Session             [N]

   AH = D0h
   DH = FFh
   AL = password flag
       FFh no password
       0Fh password at ES:DI
   ES:BX -> LAT session control block (see #3398)
   ES:DI -> 16-byte blank-padded password (optional)

Return: AH = 00h success
       DL = handle

See Also: AX=D000h

Format of LAT Session Control Block:
Offset Size    Description (Table 3398)
 00h 18 BYTEs  service name
 12h 18 BYTEs  node name (future use)
 24h 18 BYTEs  port name (future use)
 36h   DWORD   -> session stopped post routine
 3Ah   DWORD   -> service table overflow post routine
 3Eh   DWORD   -> transmit post routine
 42h   DWORD   -> receive post routine
 46h   WORD    session status
       04h circuit failure
       08h stop slot received
---LAT v???---
 48h   WORD    slot state (LAT driver use)
 4Ah   WORD    local credits (LAT driver use)
 4Ch   DWORD   -> VCB (LAT driver use)
 50h   WORD    backward slot (LAT driver use)
 52h   WORD    forward slot (LAT driver use)
 54h   WORD    remote slot ID (LAT driver use)
 56h   WORD    local slot ID (LAT driver use)
 58h   WORD    slot byte count (LAT driver use)
 5Ah   BYTE    remote credits (LAT driver use)
 5Bh 255 BYTEs transmitted data slot
15Ah   BYTE    number of receive data slots (4 recommended)
15Bh   BYTE    number of occupied slots
15Ch   BYTE    index of next receive slot to use
15Dh   BYTE    index of current receive slot
15Eh   WORD    pointer to first received character
160h  N WORDs  pointers to receive slots (buffers); each is 259 bytes
     259N BYTEs    buffers

Note:  set post routines to 0000h:0000h if polled operation will be used
---LAT v4.1.17---
 48h   WORD    session state (LAT driver use)
 4Ah   BYTE    local credits (LAT driver use)
 4Bh   DWORD   -> VCB (LAT driver use)
 4Fh   WORD    backward slot (LAT driver use)
 51h   WORD    forward slot (LAT driver use)
 53h   BYTE    remote slot ID (LAT driver use)
 54h   BYTE    local slot ID (LAT driver use)
 55h   BYTE    slot byte count (LAT driver use)
 56h   BYTE    remote credits (LAT driver use)
 57h 255 BYTEs transmitted data slot
156h   BYTE    number of receive data slots (4 recommended)
157h   BYTE    number of occupied slots
158h   BYTE    index of next receive slot to use
159h   BYTE    index of current receive slot
15Ah   WORD    pointer to first received character
15Ch  N WORDs  pointers to receive slots (buffers); each is 259 bytes
     259N BYTEs    buffers

Note:  set post routines to 0000h:0000h if polled operation will be used