rem: static void update_cursor(unsigned int x, unsigned int y)
add: update_cursor(unsigned int x, unsigned int y)
context: static void update_cursor(unsigned int x, unsigned int y){	short int pos = y*columns + x;	out8(TEXT_CURSOR_LO, TEXT_INDEX);	out8((char)pos, TEXT_DATA);	out8(TEXT_CURSOR_HI, TEXT_INDEX);	out8((char)(pos >> 8), TEXT_DATA);}