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  Interrupt:   21h     Function:   44h     Subfunction:   0Ch
 
  Title:       IOCTL: Generic I/O Control for Character Devices
               [Version 3.2+]
 
  Description:
 
     Provides a general-purpose mechanism for communication between
     application programs and character device drivers.
 
     Input                              Output
 
     AH = 44h                           If function successful
     AL = 0Ch                             Carry flag: clear
     BX = Handle                        And if called with CL = 65h,
     CH = Category (major) code:        6Ah, or 6Bh
          00 = Unknown                    DS:DX = segment:offset of
          01 = COM1, COM2, COM3, or               parameter block
               COM4 [Version 3.3]
          03 = CON (keyboard and        If function unsuccessful
               display) [Version 3.3]     Carry flag: set
          05 = LPT1, LPT2, or LPT3        AX = Error code (01h)
               [Version 3.2]              See: ◄Error codes►
     CL = Function (minor) code:
          45h = Set Iteration Count
                [Version 3.2]
          4AH = Select Code Page
                [Version 3.3]
          4CH = Start Code Page
                Preparation
                [Version 3.3]
          4DH = End Code Page
                Preparation
                [Version 3.3]
          5Fh = Set Display
                Information
                [Version 4.0]
          65h = Get Iteration Count
                [Version 3.2]
          6AH = Query Selected Code
                Page [Version 3.3]
          6BH = Query Prepare List
                [Version 3.3]
          7Fh = Get Display
                Information
                [Version 4.0]
     DS:DX = segment:offset of
             parameter block
                                    -♦-