INT 10h,  01h (1)        Set Cursor Size

    Adjusts the size of the cursor by setting its start and end lines.

       On entry:      AH         01h
                      CH         Cursor start line (bits 4 to 0)
                      CL         Cursor end line   (bits 4 to 0)

       Returns:       None

       Registers destroyed:      AX, SP, BP, SI, DI

  --------------------------------------------------------------------------
          Cursor Start and End line values (CH and CL)

                            Legal               Default
      Adapter            Start  End         Start      End
       CGA                 0     7            6         7
       MDA                 0    13           11        12
       EGA                 0    13          6(11)     7(12)  Depends on mode
  --------------------------------------------------------------------------

       Notes:         Line numbering starts at the top of the character
                      block (0) and increments downward. If you specify an
                      end line lower than the start line, a two-part
                      "wraparound" cursor is displayed.

                      There is only one cursor size for all video pages.

                      The cursor blink may not be disabled (it's caused by
                      the hardware), but you can make the cursor
                      invisible. To do this, position the cursor--with
                      Service 02h--offscreen in a nonprintable location
                      (such as row 25).

                      Setting bits 5 or 6 will cause erratic results, from
                      strange blinking to no cursor. Do not use this
                      technique to make the cursor invisible. It may not
                      work on some machines.

                      This service affects text-mode displays only. There
                      is no cursor display in any graphics mode.

                      Service 03h returns the current cursor size.