In this course, we will be using the mainframe computer system at Marist College in Poughkeepsie, New York. The operating system involved is z/OS, the latest version of MVS.
To use the Marist computer, we will need to be able to use a number of pieces of software. In some cases, there are options.
To initialize your account at Marist, to change your password as needed and to do a number of other tasks, you need to be able to connect to the system using a terminal emulator program.
When you use the terminal emulator, you establish a TSO session, interacting with z/OS. The mainframe software is known as ISPF. It runs in text mode and is menu-based.
You need to be able to create program files, run them on the Marist system, and retrieve the resulting output files. Here is where there are some options:
In any case, you don't want output files piling up at the Marist end, and the only way to delete them is to use TSO.
Thus, you need to learn to use TSO and ISPF. The Lab Training exercise focuses on these.
Software tools
This is a terminal emulator program. It should be available in the labs under "Lab Applications". If you would like to have a copy of your own, you may be able to download it from the CSCI department web site: select "Resources and Publications" and then "Computing Resources".
This is another terminal emulator program. It should also be available from the CSCI department web site. It is intended for Windows XP, Vista or later.
This program, written by John Berezinski of our department, can be used to submit jobs, check on their completion, and retrieve the output. It is also available from the department web site. It does not do everything we need to do involving the Marist site, but it may be very useful. It can also be downloaded from the CSCI department web site, along with its instructions. It is very easy to use.
Quite recently, some students here at NIU, working on an independent study project, have created a web-based interface to the Marist site. You can investigate this at the following URL:
https://webjcl.aws.af.cm/
There are other ftp programs available. Not all of them work equally well for our purposes. You may want to try the command-line ftp program built into Windows, which is documented in the Windows help system. The mar_ftp program actually uses the Windows ftp to do its work.
It is possible to write your program files under LINUX, submit them using a LINUX ftp program, and retrieve the output files the same way. You can find instructions on doing all this on the department web site.
As we are writing code, we will need a text editor. Many are available, and programmers usually have their own favorites. You can probably survive using the Windows Notepad editor, or you can use the ISPF system at Marist. In any case, you should create plain ASCII text files. (Do not use TAB characters.)
These are the actual utilities IBM provides for our use. TSO appears to give us the ability to interact with the mainframe. (It is probably more accurate to say we interact with a server-side program.) Inside TSO, we use ISPF as a working environment in which we can create, edit, delete, and copy files, as well as many other tasks. ISPF includes an editor which may be somewhat different from other editors you have examined.
How do we use mar_ftp?
Read the instructions for mar_ftp. You will need to create a mar_ftp directory (or folder) and copy mar_ftp into it.
Create your job file using a text editor. In general, a job file will have the extension "JCL". Copy it into the mar_ftp directory. Run mar_ftp. Option 1 allows you to submit a job; you will be asked for its name. (If it is not in the mar_ftp directory, you can supply the path as well.) Option 2 will list the jobs on the job queue. Usually one of these has a number of the form TSUnnnnn; this is the TSO session itself. Other jobs have numbers of the form JOB0nnnn. Notice the job number. Option 3 will allow you to fetch the output from the job; you will be asked for the job number.
When you fetch the job's output, two files will now appear in the mar_ftp directory: one named for the job number with no extension another with the same name but with extension "txt". The "txt" file is the job's output but with the carriage-control characters interpreted.
You can now print either of these files using Notepad or some other text editor or word processor. Print it in landscape format using a monospaced font such as Courier New. Set margins so the lines will not be wrapped. (Using MS Word, a reasonable choice is Courier New, 9 point, 0.3" left and right margin.)
Why do we need TSO and ISPF?
While mar_ftp and other ftp programs can do a number of things for us, they are not able to delete the output files from the Marist system. To do so:
On the ISPF Primary Option Menu, select option 13, "SDSF". The first time you do this, type "OWNER logonid" where it says "COMMAND INPUT", using your own KC number where it says "logonid". (Do not type the quotation marks.)
SDSF does a number of useful tasks. Use command H to look at the "held output" queue. This gives you a list of the files you have in the queue. To delete a file, type C or P in the column labeled "NP" next to the file's name (which will look like "TSUnnnnn" where "nnnnnn" is the job number). Press Enter. A box pops up asking if you want to process that command (option 1 of the options listed in that box). Press Enter to confirm. The file should now disappear from the list.
Also, if you need to change your password, you cannot do this using mar_ftp, and you will have to use the TSO system.
As TSO and ISPF are the industry standard, available at every mainframe site, it is an excellent idea to learn how to use them.