Updating instructions for 15-May-1983 release (Save/Get ver 2).


IGNORE THESE INSTRUCTIONS UNLESS YOU ALREADY HAVE AN OLD AIPS
RUNNING THAT YOU WANT TO CONVERT TO THE NEW FORMAT.

Principles:  Once again, we have found it necessary to make major
changes in AIPS data files.  User numbers at NRAO will soon go to
four digits.  Since many files carry the user number as part of
the file name and this number can be only 3 digits, we are now
carrying the name internally as a hexadecimal number.  The user,
of course, will still use his decimal number and see the decimal
number on all print out.  This update requires running a file
renaming program, CATCHR, described below.  Any OLD area becomes
virtually useless, since the old AIPS routines will look for a
particular user file with the decimal encoding instead of the
hexadecimal encoding.  An added feature of the new scheme is that
we can now have 255 extension files instead of the old 99.

  The program to rename all the data files to the new format is
called CATCHR.  This program must NOT be run for the same data
file more than one.  CATCHR will be compiled and linked by the
installation procedure.  To run this program after the installation
log on to AIPS and from the DCL level ($ prompt) type :

$ RUN [AIPS.new.LOAD]CATCHR

  CATCHR first calculates the number of ME, and MS files you have
and ONLY if you have more than 9 asks the question:

DO BASIC FILES? (A3) - SAY 'YES' ONLY ONCE

  The first time you run this program you should type in YES (The
A3 indicates the program is expecting a 3 character input).  The
SAY 'YES' ONLY ONCE is to remind you that if you run the program
again for any reason (for example for another range of user numbers)
type in NO.

  The next (or possibly first) prompt is :

ENTER RANGE OF USER NUMBERS (2I4), DEFAULT=1,999

  The (2I4) reminds you to enter a range such as 1 to 800 as 00010800.
a zero entry or a carriage return will default to the range 1 through
999.

  The next prompt is:

ENTER RANGE OF DISK VOLUMES (2I2), DEFAULT=ALL

  The (2I2) reminds you to enter a range such as 1 to 3 as 0103.
A zero entry or a carriage return will default to all disks that
are known to AIPS (this number was set during the installation).

  The next prompt allows you to review your entries and reenter them
if you made a mistake.

USERS :  uuu  uuu  DISKS :  d  d     1=OK, 0=REENTER  (I1)

  After you enter a 1 the program will rename all data files
printing a progress report as it goes.  If there are large
gaps between two user numbers the program may not print anything
for a few minutes.

  Do not forget to run the program for any demountable user packs
that contain AIPS data.  Make sure you specify the range
of disk volumes to limit renaming to that pack.

  Any data recovered from backup tapes that were written before the
installation of the new system will need CATCHR run for the
particular user number involved.  You must make sure
that there is no user number conflict between the old decimal number
on tape and the new hexadecimal numbers on disk before reading in
the data.  That is, if the user on tape is decimal 10 there can
not be data for decimal user number 16 (hex 10) on disk.

  If you look closely at the top of this document, you may notice
evidence for another addition to AIPS.  Save/Get files now
have version numbers.  This AIPS and its succesors will refuse
to read incompatible Save/Get files.  The Save/Get version of
the 15MAY83 AIPS is 2.  All older versions are 0.  A new
program (DELSG) exists to allow the AIPS manager to delete
SG files that can not be read by either the OLD or NEW AIPS.
