define(BLOCKINGFACTOR,10)
common /blkio/ blkptr, blkn, nread, reclen, efbk, ffby,
               fixed, seq, nospan, blkbuf
 
integer blkptr				# pointer to blkbuf
integer blkn				# next virtual block number to read
integer nread				# number of words read
integer reclen				# record length for fixed length file
integer efbk				# EOF block number
integer ffby				# first free byte in EOF block
logical fixed				# .true. if file has fixed len records
logical seq				# .true. if file has sequenced records
logical nospan				# .true. if nospanblocks
integer blkbuf(0:BLOCKINGFACTOR*256-1)	# block buffer