Create new object

        Entry:
          AH = 12h
          BH = 01h
          BL = object
               00h (DV 2.0x only) handle is DWORD on top of stack
               01h (DV 2.0x only) use task's window handle
               02h (DV 2.0x only) given task's mailbox
                   (task's handle on stack)
               03h (DV 2.0x only) current task's mailbox
               04h (DV 2.0x only) given task's keyboard
                   (task's handle on stack)
               05h (DV 2.0x only) current task's keyboard object
               08h WINDOW class
               09h MAILBOX class
               0Ah KEYBOARD class
               0Bh TIMER object (counts down 32-bit time in 10ms increments)
               0Fh POINTER object
               10h PANEL object
          STACK: (if window object or WINDOW class)
                 DWORD address to jump to (no new task if high word == 0)
                 DWORD (reserved) 0 = non-task window, FFFFh = task window
                 DWORD bytes for task's private stack (FFFFh == default
                                                       of 0100h)
                 DWORD bytes system memory allocation (0 == none,
                                                       -1 == default)
                 DWORD window size, columns
                 DWORD window size, rows
                 DWORD length of window title
                 DWORD address of window title

        Return:
          DWORD on top of stack is new object handle

        Note:   If a new task is created, it is started with
                AX = BX = CX = SI = DI = BP = 0
                DX = segment of parent's object handle
                DS = ES = SS = segment of private stack
                               (and new task's object handle)