BZ_HDR_0
blockSize100k = *mode-BZ_HDR_0;
bsPutUChar ( s, (UChar)(BZ_HDR_0 + s->blockSize100k) );
if (s->blockSize100k < (BZ_HDR_0 + 1) ||
s->blockSize100k > (BZ_HDR_0 + 9)) RETURN(BZ_DATA_ERROR_MAGIC);
s->blockSize100k -= BZ_HDR_0;