INT 31H 0400H: Query DPMI Version

                                                    Compatibility: DPMI 0.9+ 
 Expects: AX    0400H
          ──────────────────────────────────────────────────────────────────
 Returns: CF    NC (this fn always succeeds)
          AH    DPMI major version
          AL    DPMI minor version; e.g AX=030aH means version 3.10
          BX    info flags (see below)
          CL    processor type:  02H = 80286
                                 03H = 80386
                                 04H = 80486
                                 05H = Pentium
                                 >5  = reserved for future Intel CPUs
          DH    current value of virtual master PIC base interrupt
          DL    current value of virtual slave PIC base interrupt
          ──────────────────────────────────────────────────────────────────
    Info: This obtains the DPMI version number supported by the DPMI host
          and some other info.

       BX contains some relevant bit flags:
           1 1
          ┌5┬4┬ - ┬3┬2┬1┬0┐
          │0 0...0 0│v│r│b│
          └─┴─ - ─┴─┴╥┴╥┴╥┘ bit  mask
                     ║ ║ ╚►  0: 0001H 1=host is 32-bit implementation
                     ║ ║              0=host is 16-bit
                     ║ ╚══►  1: 0002H 1=returns to real mode for ints
                     ║                0=returns to Virtual 86 mode for ints
                     ╚════►  2: 0004H 1=virtual memory supported; 0=not

    Note: ■ See INT 2fH 1687H and INT 31H 0401H for related info.

          ■ Use INT 31H 0e00H to check for the presence and status of a
            numeric coprocessor.

See Also: DPMI API
          INT 2fH: Multiplex Interrupt
          DOS Functions
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