Indeed! I created a sample file, and the advantage of NETDATA over
DISK DUMP (file size of the NETDATA version was nearly half of the
DISK DUMP version) seems to come from the additional control
fields added by DISK DUMP to each record. For comparison, I tried
the same file with CARD DUMP, which DOES pack blanks, and my
486-DISK DUMP-record file became a file of 6 records! Talk about
performance increase!
 
PS: The original file was 112 records, all blank and record size of 200,F.
    NETDATA grew this file slightly to 287 records, record size of 80,
    DISK DUMP (get ready) produced a file of 451 records,   size   80 !
 
Regards, -turgut