FDSECSIZE
if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
sz *= FDSECSIZE;
toff = sec * FDSECSIZE;
tsz = sc->nsectors * FDSECSIZE;
#define MAXTRKSZ (22 * FDSECSIZE)
lp->d_secsize = FDSECSIZE;
lp->d_secsize = FDSECSIZE;
bp->b_bcount = FDSECSIZE;
if (lp->d_secsize != FDSECSIZE ||
bp->b_bcount = FDSECSIZE;