Int 2F Fn D102  - Mdebug Command Driver - Execute Interpreter Command      [G]

   AX = D102h
   BL = first character of the interpreter command
   BH = last character of the interpreter command (or blank)
   DS:SI -> parameter for the interpreter command as ASCIZ string
   DS:DI -> MDEBUG data structure (see below)

Return: AL = FFh
   CF set on error
       AH = error number
       01h syntax error
       02h first shell of the command.com is activ
       03h esc pressed
       04h break pressed
       05h DOS is busy
       06h command ended
       07h division by zero
       08h invalid display driver
       09h invalid command driver
       0Ah error 8 and 9
       0Bh unknown error
       0Ch new error
           DS:SI -> ASCIZ error message (max 30 characters)
          else unknown error
   CF clear if successful
       AH = return code
       00h continue processing the command line
       01h leave MDEBUG popup session
       02h leave MDEBUG popup session and automatically popup again
           if the InDOS flag is zero
       03h not used (same as 00h)
       04h not used (same as 00h)
       05h put new command line into the input buffer,
           DS:SI -> new command line (ASCIZ string, max 66 chars)
       06h process new command line
           DS:SI -> new command line (ASCIZ string, max 66 chars)
          else unknown status, but continue processing commmand line

Note:  this function must end with a far call to the old INT 2F handler (with
     registers unchanged) if the driver does not support the interpreter
     command in BX.  Otherwise, the driver must not chain to the old
     INT 2F.

Format of MDEBUG data structure:
Offset Size    Description
 00h   WORD    register SE
 02h   WORD    register OF
 04h   WORD    register FS
 06h   WORD    register FO
 08h   WORD    register AX
 0Ah   WORD    register BX
 0Ch   WORD    register CX
 0Eh   WORD    register DX
 10h   WORD    register SI
 12h   WORD    register DI
 14h   WORD    register DS
 16h   WORD    register ES
 18h   WORD    register BP
 1Ah   WORD    register SS
 1Ch   WORD    register SP
 1Eh   WORD    register FL (flags)
 20h   WORD    register R0
 22h   WORD    register R1
 24h   WORD    register R2
 26h   WORD    register R3
 28h   WORD    register R4
 2Ah   WORD    register R5
 2Ch   WORD    register R6
 2Eh   WORD    register R7
 30h   WORD    register R8
 32h   WORD    register CS, return-address
 34h   WORD    register IP, return-address
 36h   DWORD   saved pointer to data for key <F6> (v1.60)
       saved monitor address (v1.70)
 3Ah 12 WORDs  saved register values on last popup entry (for <F8> key)
       (original register values at popup entry of MDEBUG)
       AX, BX, CX, DX, SI, DI, DS, ES, BP, SS, SP, flags
 52h 12 WORDs  saved register values on last popup exit (for <SHIFT-F8> key)
       AX, BX, CX, DX, SI, DI, DS, ES, BP, SS, SP, flags
 6Ah   DWORD   address of the DOS-invars-table
 6Eh   DWORD   address of the InDOS flag
 72h   WORD    offset of the register which is used for the segment of the
       first monitor window
 74h   WORD    offset of the register which is used for the offset of the
       first monitor window
 76h   WORD    name of the register which is used for the segment of the
       first monitor segment
 78h   WORD    name of the register which is used for the offset of the first
       monitor window
 7Ah   WORD    pseudo register 1
 7Ch   WORD    pseudo register 2