CHS_rw
error = CHS_rw(rw, dev, cyl, head, sect, n, p);
int CHS_rw (int, int, int, int, int, int, void *);
error = CHS_rw(rw, dev, cyl, head, sect, n, p);
int CHS_rw (int, int, int, int, int, int, void *);