Int 7A Fn 09  - IBM 3270 Workstation Program API - Multi-dos               [I]

   AH = 09h
   BX = 8020h
   CX = 00FFh
   ES:DI -> control block
   DX = ID of INDJQRY
       get environment size
      = ID of INDJASY
       request DOS functions from workstation
      = ID of MEMORY
       AL = function
           01h allocate memory
           02h deallocate memory
           03h modify allocated size

Return: ???