crctab_p
crctab_p = (ulg near *) nearmalloc (256*sizeof(ulg));
if (crctab_p == NULL) {
crctab_p[n] = c;
# define MARK_CRCTAB_FILLED crc_table = crctab_p
ulg near *crctab_p; /* temporary pointer to allocated crc_table area */