Int 2F Fn 7A20  - Novell Netware - Dos Requester V1.03+ - Get Vlm Calla A  [N]

   AX = 7A20h
   BX = 0001h

Return: AX = 0000h if request was handled
       ES:BX -> CallA entry point (see #2579)

See Also: AX=7A20h/BX=0000h

(Table 2579)
Call VLM CallA entry point with:
   AX = function
       0000h submit
       0001h cancel (not implemented)
   ES:DI -> Overlay Asynchronous Control Block structure (see #2580)

Return: DI, DS, ES preserved; all other registers may be destroyed
   interrupts disabled
Desc:  asychronously call the specified VLM and then return to caller, which
     might be another VLM

Format of Overlay Asynchronous Control Block (OACB):
Offset Size    Description (Table 2580)
 00h   DWORD   link to next OACB, 0000h:0000h if last (filled by VLM.EXE)
 04h   DWORD   callback address or 0000h:0000h
 08h   BYTE    InUse flag (00h if complete) (set by VLM.EXE)
 09h   BYTE    flag, reserved for VLM use
 0Ah   WORD    destination VLM
 0Ch   WORD    destination function
 0Eh   WORD    temporary storage for VLM.EXE
 10h  6 BYTEs  reserved
 16h  6 DWORDs EAX,EBX,ECX,EDX,ESI,EDI
 2Eh  4 WORDs  DS,ES,FS,GS (FS and GS not used)