Int 2F Fn A189  U - Biologic Hramdev.sys - API                             [m]

   AX = A189h
   BX = subfunction
       0000h set ???
       0001h remove ???
       0002h get status ???
       0003h enable ???
       0004h disable ???
       0005h set ??? flag
       0006h clear ??? flag
       0007h set ??? flag
       0008h clear ??? flag
       0009h set ???
   ES:DI -> function-specific arguments
       if func 0000h: 20-byte buffer containing ???
       if func 0001h: 20-byte buffer for returned ???
       if func 0002h: 16-byte buffer for returned ???
       if func 0009h: WORD containing ???

Return: BX = A189h if installed
   AH = status
       00h successful
       FFh failed or invalid function number
Program: HRAMDEV.SYS is a part of the shareware package HRAM by Biologic which
     provides improved high memory access under MS-DOS 5.0

Note:  functions 00h and 01h use a stack of four entries; function 01h always
     removes the values stored with the most recent function 00h call
     which has not yet been matched with a function 01h call.