@@
A. Summary of an AIPS installation

1. Installing an AIPS for the first time.

   First read the instructions.  A description of the chapters and
their purpose follows:

   B. The AIPS environment on the VAX.

     This chapter describes the directory structure, the logical
   names, etc. of AIPS.  It is possible to install AIPS without
   completely understanding this chapter, but the details found
   here can give some insight into how AIPS can be tailored to
   fit the needs of your site.  This chapter is also important for
   people who want to program in AIPS, or to set up AIPS in a
   non-standard  way, and is useful for trouble shooting if things
   don't work.
 

   C. Step by step instructions for installing AIPS

     The most important instructions.  If you understand these
   instructions enough to fill out the AIPS installation work sheet,
   you know enough to try to install AIPS.

   D. Shortcut installation procedure.

      Since we can no longer fit all of AIPS onto one 1600 BPI tape,
   we have put the files needed for the shortcut procedure onto a
   second tape for those sites that have requested a 1600 BPI tape.
   Since most sites can not use this procedure, we do not send this
   tape unless it is requested.  Sites that receive a 6250 BPI tape
   will continue to receive all the files necessary for the shortcut
   procedure.
 
      The shortcut procedure does the same things as the standard
   procedure except that instead of compiling and linking all of
   the AIPS code, it just loads the executable modules from tape.
   If you have an AP 120B and are on VMS 3.x, and do not need to
   change any widely used subroutines, like ZDCHIN, and you have
   requested the second tape or a 6250 BPI tape, you can use
   the shortcut procedure.  The first part of the shortcut
   procedure asks the same questions as the standard procedure.
   These questions and possible answers are described in chapter C.

   E. Trouble shooting.

      If AIPS doesn't work after the installation, this is the chapter
   for you.  Help is also available from the AIPS programming group in
   Charlottesville.  If your VAX has a dial in modem that can be used
   to look at the current status of the files, logical names, etc.,
   be sure to mention it, since this could make solving a subtle
   problem much easier.

   F. Programming in AIPS.

     This chapter contains a few tips on the Vax specific aspects of
   programming in AIPS.  The main manual on programming in AIPS can
   be found in [AIPS.new.DOC.TEXT]ALL.MEM.

   G. Listings of the installation procedures.

      This chapter could be useful if things go wrong or hang up or
   if you want to install AIPS in a nonstandard way.

  After reading the instructions and filling out the Installation
Worksheet, decide on whether you want to use the standard procedure
or the shortcut procedure.  Then proceed as described in chapter
C or chapter D.

2. Updating an existing AIPS

  First back up your current AIPS system.  Some updates can become
very tricky.  If you have important data in your AIPS system, backing
up before attempting an update is a must.

  Next review the installation instructions and fill out the
Installation Work Sheet.

  Since the 15NOV82 version of AIPS we have provided the capability
to run two different versions of AIPS programs accessing the same
data files.  These versions are called OLD and NEW.  If you
currently (before the update) have an OLD and a NEW area, you will want
to delete all of the OLD code, libraries, executable modules, etc. by
logging into AIPS, setting the default to [AIPS.old] where "old" is the
the name  you used for your oldest area (usually the release date of
that version), and do a DEL [...]*.*;* .  If you only have one area
(a NEW area), decide if you have the disk space to run both an OLD and
a NEW AIPS, and if the file structures allow them to share the same
data base.  If not, log on to AIPS, set the default to [AIPS.new] and
DEL [...]*.*;* .  If you want to have two areas, you can set this up
during the installation by responding correctly to the prompt
ENTER THE STRING TO USE FOR OLD VERSION.

   Running an OLD version also requires changing a string that programs
AIPS and BATER use to determine whether they are the OLD version or the
NEW version.  This string is currently hard coded in the programs (sorry).
The best time to change the programs is before the installation so that
the logical assignments used by the compile and link procedures are
still pointing to the subdirectories that will become the OLD
subdirectories after the update.  To do this logon to AIPS, get to the
system level ($ prompt) and do an @CDNEW.  This will set the default
directory and logical assignments to the values needed to run the
compilation procedures.  Then edit program AIPPGM:AIPS.FOR and
change the line that is about the 46th one from the top from

      DATA PRGNAM, MYVERS /'AI','PS','  ', 'NEW:'/
to
      DATA PRGNAM, MYVERS /'AI','PS','  ', 'OLD:'/

   Then edit program AIPPGM:BATER.FOR and change the line which is about
30 lines from the top from

      DATA MYVERS /'NEW:'/
To
      DATA MYVERS /'OLD:'/

Then compile and link both programs by executing the following two
command lines:

@ACOMLNK AIPS
@ACOMLNK BATER

   To update the source code and the work data files, run either
the standard installation procedure or the shortcut installation
procedure just as if you were installing an AIPS for the first time.

  Next you must update the AIPS data files.  AIPS is still undergoing
rapid development which, unfortunately, often requires changing file
structures.  Since the 15NOV82 version of AIPS we have been producing
instructions for each new version for updating the previous
version. We provide conversion programs for catalog files when their
format changes, but other files such as SAVE/GET files must be deleted
when they change.  Although you will only have to go through one
installation procedure (the loading, compiling and linking part), you
must follow the instructions for file format updates for EVERY version
IN ORDER that came after your old version.

   Finally you must run a program that deletes all of the Save/Get files
that are incompatible with the current system.  To do this logon to AIPS,
get to the system level ($ prompt) and run program [AIPS.new.LOAD]DELSG
where 'new' is the string you are using to designate your current system.
The first prompt issued by DELSG is

LOWEST STILL USABLE SAVE/GET VERSION NUMBER (I4)

If you are running both an OLD and a NEW AIPS then use the Save/Get version
number printed at the top of the supplemental updating instructions provided
for the OLD release.  If you are running a NEW version only, use the
Save/Get version printed at the top of the instructions for this release.
The (I4) in the prompt means you must use the FORTRAN I4 format.  That is
the number 4 is entered as 0004 .  The next prompt is:

USER NUMBERS TO DO (2I4) DEFAULT=    0 999

Enter your lowest and highest user number, or if you don't mind waiting a
few extra minutes while the program searches through the entire range,
just press RETURN and update all users between 0 and 999.  The (2I4) in
the prompt reminds you to use FORTRAN 2I4 format for your input.  For
example the numbers 100 to 500 would be entered as 01000500 .

   The execution of DELSG is the final step in the update procedure.
