Draw_Line_d ($F3DF)
This routine will draw a line from the current pen position, to the point specified by the (y,x) pair specified in the D register. The current scale factor is used. Before calling this routine, $C823 should be = 0, so that only the one vector will be drawn.
ENTRY:
DP = $D0
A-reg = relative y position
B-reg = relative x position
EXIT:
X-reg is incremented by 2
D-reg trashed