These routines force the scale factor to 0xFF, 0X7F, or the A register, and then move the pen to the (y,x) position pointed to by the X-register. The X-register is then incremented by 2.
DP = $D0
X-reg points to the (y,x) coordinate pair
B-reg contains the scale factor (Moveto_ix_b only)
X-reg has been incremented by 2