-extern unsigned short *screen_pos(int currcons, int w_offset, int viewed);
-extern u16 screen_glyph(int currcons, int offset);
-extern void complement_pos(int currcons, int offset);
-extern void invert_screen(int currcons, int offset, int count, int shift);
+extern unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed);
+extern u16 screen_glyph(struct vc_data *vc, int offset);
+extern void complement_pos(struct vc_data *vc, int offset);
+extern void invert_screen(struct vc_data *vc, int offset, int count, int shift);