INT 10 - VIDEO - SET TEXT-MODE CURSOR SHAPE
        AH = 01h
        CH = bit 7    should be zero
             bits 6,5 cursor blink
                     (00=normal, 01=invisible, 10=erratic, 11=slow)
                     (00=normal, other=invisible on EGA/VGA)
             bits 4-0 top scan line containing cursor
        CL = bottom scan line containing cursor (bits 0-4)
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
BUG:    AMI 386 BIOS and AST Premier 386 BIOS will lock up the system if AL
          is not equal to the current video mode
SeeAlso: AX=CD05h