===============================================================================
                                Introduction
===============================================================================

File Transfer Protocal (FTP) is used to transfers files between two computers.
To use FTP you need to have an account on the remote computer. However, systems
can establish an "anonymous FTP" account which will permit limited access to a
host. To use a host's anonymous FTP account login as "anonymous" using you're
e-mail address as the password.  

===============================================================================
                             PPI/PDS Anonymous FTP
===============================================================================

The PPI node of PDS offers software, data and documentation through an
anonymous FTP account. The account can be accessed on pdsppi.igpp.ucla.edu
(128.97.68.54).  Under this account PDS/PPI software, data, documents and
information can be found.  The core subdirectories are:

     DATA :      The location where data is staged for FTP retrieval.
     DRIVERS :   Non-PDS supported CD-ROM reader hardware drivers for older
                 systems.
     ERRATA :    Information about data products.
     SOFTWARE :  Software for various platforms.

You may also find other directories which provide direct access to PDS/PPI data
holdings. The directories: bin, dev, etc, usr, and var are system directories
and do not contain anything useful for the user.
 
===============================================================================
                                FTP Commands
===============================================================================

The commands available in anonymous FTP are the same as those available in a 
normal FTP session. Some commands may differ from computer to computer. A list
of commands can usually be displayed by typing ? or help at the "ftp" prompt.
Your installation may provide a on-line documentation for FTP. On UNIX
machines, this can be retrieved by typing 'man ftp'.

The following is a short list of some of the commands available during an
FTP session:

ascii
   change to "ascii" mode for transfer of ASCII files. With "ascii" mode a
   translation of the newline convention on different platforms is performed
   during transfer.

bin
   change to binary mode for transfer of binary or image files.

cd REMOTE_DIRECTORY
   change the working directory to REMOTE_DIRECTORY on the remote computer.

dir
   lists directory contents in the current working directory on the remote
   computer showing as much information about each files as the remote system
   can provide.

get REMOTE_FILE LOCAL_FILE
   retrieves the REMOTE_FILE and places the contents in LOCAL_FILE.
   If a LOCAL_FILE is not specified, the contents will be placed into a
   file with the name REMOTE_FILE on the local computer.

lcd LOCAL_DIRECTORY
   change the working directory to LOCAL_DIRECTORY on the local computer.

ls
   lists the names of each file in the current directory on the remote system.

pwd
   shows the current working directory on the remote computer .

quit
   ends the FTP session.

===============================================================================
                     Instructions on Using Anonymous FTP
===============================================================================

The following are instructions on using Anonymous FTP to obtain a copy
of PDS/PPI provided software:

1. Initiate an FTP session.

   At your system prompt type: ftp pdsppi.igpp.ucla.edu
                               or
                               ftp 128.97.68.54

2. Login as "anonymous".

   You will be prompted for a login name. Type 'anonymous' at the prompt.

3. Enter your e-mail address as the password.

   You will be prompted for a password. Although it is not necessary to enter
   a password, it is customary to enter your e-mail address.

4. Change directory to the software directory located at "SOFTWARE".

   Once the login to the anonymous FTP server is completed successfully, the 
   ftp prompt will appear (ftp>). To obtain software, change directory to 
   "SOFTWARE". Example:

   ftp> cd SOFTWARE

5. List the available software for your particular platform using 'ls'.

   Various directories exists under "SOFTWARE" containing software for a number 
   of platforms. A 'ls' command will list what is available. The following is
   an example of what you may see:

ftp> ls

   200 PORT command successful.                                              
      
   150 ASCII data connection for /bin/ls (128.97.68.39,1529) (0 bytes).      
      
   total 376                                                                 
      
   drwxr-xr-x   6 1000     10          1536 Jun  6 21:00 DATA                
      
   drwxr-xr-x   3 1000     1000         512 Nov  2  1993 DRIVERS             
      
   drwxr-xr-x  12 1000     10           512 May  9 20:46 ERRATA              
      
   -rw-r--r--   1 1000     1000      109234 Mar 28 18:51 
Jupiter_archive_status.eps
   drwxr-xr-x   9 1000     10           512 Jul  8  1994 SOFTWARE            
      
   dr-xr-xr-x   2 0        1            512 Jun 12 18:47 bin                 
      
   dr-xr-xr-x   2 0        1            512 Jun 12 18:52 dev                 
      
   drwxr-xr-x   2 0        1            512 Mar 31  1994 disk1               
      
   drwxr-xr-x   2 0        1            512 Mar 31  1994 disk2               
      
   drwxr-xr-x   2 1000     1000         512 Aug 12  1994 disk3               
      
   drwxr-xr-x   2 0        1            512 Mar 31  1994 disk7               
      
   dr-xr-xr-x   2 0        1            512 Jun 12 18:48 etc                 
      
   -rw-r--r--   1 64       15         47221 May  9  1994 
pvo_data_questionaire.ps  
   drwxrwxrwx   2 0        1           7168 Jun  8 20:25 temp                
      
   dr-xr-xr-x   3 0        1            512 Jun 12 18:48 usr                 
      
   drwxr-xr-x   3 0        1            512 Jun 12 18:49 var                 
      
   226 ASCII Transfer complete.                                              
      
   1021 bytes received in 0.66 seconds (1.55 Kbytes/sec)                     
      

6. Retrieve files.

   Software to convert binary flatfiles to ASCII for SOLARIS machines is locat-
   ed in SOLARIS/BIN. By convention executables are placed in a "BIN" or "bin"
   directory. The following is what you may do to retrieve the PPI/PDS software
   "ffextract":

ftp> cd SOLARIS/BIN

  Since ffextract is the binary executable, you will have to change the
  transfer mode to binary prior to copying the executables.

ftp> bin

  The 'get' command will retrieve a file and store it on your local computer.

ftp> get ffextract

  There is now a binary exacutable with the name ffextract in your local
  directory.

7. End FTP session.

  To end your FTP session, type 'quit' at the prompt.

ftp> quit