AH = 63h CX:DX = microseconds INT 18h (blocks) Get BIOS version
AH = 42h (same registers as read)
AH = 11h INT 18h ZF = 1 if no key ZF = 0 if key waiting → AX = scancode/ASCII
AH = 25h AL = lines to scroll CH = top row, CL = left col DH = bottom row, DL = right col BH = fill color INT 18h
AH = 28h AL = mode 0 = 80x25 text (16 colors) 1 = 80x28 text (400 lines) 2 = 640x400 graphics (4 planes) 3 = 640x400 graphics (16 colors) INT 18h
AH = 40h DL = drive (0=A, 1=B, etc.) INT 18h Returns: CF = 0 if OK
