Int E0  - Real/32 - "dev_map" - Get/set Serial/parallel Port Mappings      [O]

   CL = B8h
   DS:DX -> Device Map Parameter Block (DEVPB) (see #3786)

Return: nothing???
   may destroy SI,DI,DS

Format of REAL/32 Device Map Parameter Block (DEVPB):
Offset Size    Description (Table 3786)
 00h   WORD    direction (00h = get current mapping, 01h = set new mapping)
 02h  4 BYTEs  physical device IDs which map into LPT1 - LPT4
 06h  4 BYTEs  physical device IDs which map into COM1 - COM4

Note:  LPT4 and COM3/COM4 are reserved on early versions of Multiuser DOS,
     but are supported from at least CCI Multiuser DOS v7.22 onward