Int 10 Fn 01  - Video - Set Text-mode Cursor Shape                         [V]

   AH = 01h
   CH = cursor start and options (see #0012)
   CL = bottom scan line containing cursor (bits 0-4)

Return: nothing
Desc:  specify the starting and ending scan lines to be occupied by the
     hardware cursor in text modes

Notes: buggy on EGA systems--BIOS remaps cursor shape in 43 line modes, but
     returns unmapped cursor shape
   UltraVision scales size to the current font height by assuming 14-line
     monochrome and 8-line color fonts; this call is not valid if cursor
     emulation has been disabled
   applications which wish to change the cursor by programming the
     hardware directly on EGA or above should call INT 10/AX=1130h or
     read 0040h:0085h first to determine the current font height
   on some adapters, setting the end line greater than the number of lines
     in the font will result in the cursor extending to the top of the
     next character cell on the right
BUG:   AMI 386 BIOS and AST Premier 386 BIOS will lock up the system if AL
     is not equal to the current video mode

See Also: AH=03h,AX=CD05h,AH=12h/BL=34h,#3556

Bitfields for cursor start and options:
Bit(s) Description (Table 0012)
 7 should be zero
 6,5   cursor blink
   (00=normal, 01=invisible, 10=erratic, 11=slow)
   (00=normal, other=invisible on EGA/VGA)
 4-0   topmost scan line containing cursor