DROP will scan an entire mass-storage device seeking clues to the nature
of the files it contains.  Thus if you lose the directory on a valuable tape
and do not have a recent listing, DROP can be used to give you at least some
idea of the files present. The program recognizes, for instance, .BN and .SV
files, and in the later case, uses the CCB to suggest a likely candidate, ie
PIP or ABSLDR or some other system program. Of course it does not know about
any of your own special programs, but will list the starting address and the
core locations used, which is often sufficient.  In the case of ASCII files,
DROP will print the first 60 characters (sans all Carriage Returns and Line-
feeds), which again is usually enough to identify the file. Given the start-
ing block and the length, you can then copy it with the RECOVR program.

    DROP asks at the end:  'WRITE DIRECTORY?'.  Respond -only- with 'NO' (or
with just a carriage return). This option has not been properly implemented!

EX:		.R DROP
		*{output device <} {input device}
defaults:	       TTY:		DSK:

    DROP was developed by an unknown author in Prof. W.L. van der Poel's lab
at the Technical University of Delft (Holland). It was made available at the
1978 European DECUS meeting in Copenhagen.
interpretation  so you can copy (as with RECOVR) any number of blocks into a
named file.  The '/C' switch specifies 'copy' instead of 'compare' (both be-
gin with 'C', so you will just have to remember this one!) although it would
seem that the program should be able to distinguish between these operations
from the number of input 'files' specified.  The comparison feature is quite
useful after a directory crash  when attempting to match files with those on
another device.  Use the '/B' option in DIRECT to get a list of locations.

EX:		.R COPCOM
copy		*{odev:}location < {idev:} location /C=N
copy		*{odev:}filename < {idev:} location /C/F=N
compare		*{odev:} {file}  < {dev1:} loc1, {dev2} loc2 =N

     COPCOM has been used to copy several 'stranger' (non-DEC) floppies into
OS/8 files  using a byte-mode floppy handler (Newsletter #29, p15), and then
comparing them with OCOMP.   This would also be a convenient way to copy all
or part of a PDP11 floppy to an OS/8 file, or vice versa (ibid. #30, p7).