INT 21 - WORKGRP.SYS - GET API ENTRY POINT
        AX = 4402h
        BX = file handle for device "NET$HLP$"
        CX = 0008h
        DS:DX -> buffer for entry point record
Return: CF clear if successful
            AX = number of bytes actually read
        CF set on error
            AX = error code
Program: WORKGRP.SYS is the portion of Microsoft's Workgroup Connection which
          permits communication with PCs running Windows for Workgroups or
          LAN Manager
SeeAlso: AH=3Fh"WORKGRP.SYS"

Format of entry point record:
Offset  Size    Description
 00h    WORD    3633h  \ signature???
 02h    WORD    EF6Fh  /
 04h    DWORD   address of entry point
Note:   first four bytes of buffer must be 6Fh E9h 33h 36h on entry when using
          IOCTL rather than READ to get the entry point record

Call WORKGRP entry point with:
        STACK:  WORD    function number (0000h-0009h)
Return: STACK unchanged

Call WORKGRP function 00h with:
        STACK:  WORD    0000h (function "get ???")
Return: DX:AX -> data table

Call WORKGRP function 01h with:
        STACK:  WORD    0001h (function "hook ???")
Return: STACK:  DWORD   pointer to ???
                WORD    0001h (function number)

Call WORKGRP function 02h with:
        STACK:  WORD    0002h (function "unhook ???")
        ???
Return: ???

Call WORKGRP function 03h with:
        STACK:  WORD    0003h (function "reenable printer port")
                WORD    LPT port number
Return: ???

Call WORKGRP function 04h with:
        STACK:  WORD    0004h (function "disable printer port")
                WORD    LPT port number
Return: ???

Call WORKGRP function 05h with:
        STACK:  WORD    0005h (function "???")
                ???
Return: ???

Call WORKGRP function 06h with:
        STACK:  WORD    0006h (function "???")
Return: STACK unchanged
        AX = 0000h
        DX = 0000h

Call WORKGRP functions 07h-09h with:
        STACK:  WORD    0007h-0009h (NOP functions)
Return: STACK unchanged
        AX = 0001h
        DX = 0000h

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