HBLKS
if (tline == INCRMT * (HBLKS+2))
tline = INCRMT * (HBLKS+2);
blocks[0] = HBLKS;
blocks[1] = HBLKS+1;
if (H.Blocks[0] != HBLKS || H.Blocks[1] != HBLKS+1) {
(void)lseek(tfile, (long)(BUFSIZE*HBLKS-8), 0);
*ip = ((HBLKS*BUFSIZE)-8) >> SHFT;