Connecting to the UNET Mainframe
Logging On, Logging Off
The Mainframe Screen and Keyboard
The Shell Menu System
HELP: Online Documentation
Operating System Layers: CP and CMS
Managing your Mainframe Account: Passwords, Profile, Disk Space, Central Memory and More

Using CMS: Contents

Next Chapter

Connecting to the UNET Mainframe

To work with CMS, you need to tell it what to do - in other words, you need to give it commands. In order to "talk" to CMS you have to sit at a device with a keyboard and screen so you can type in commands or make selections from a menu, and see the results. Nowadays, we use microcomputers for this purpose, but in the past, many of us used IBM 3270 "terminals." Even if you use a microcomputer, CMS wants you to be running a program on that micro that emulates an old IBM 3270 terminal.

Your microcomputer must be connected to the mainframe via the Internet or campus network so that the things you type are received by the mainframe and you get the results on your screen.

For information on how to use a modem to connect to the Internet, see the document "Connecting to the Internet" .

Once your microcomputer is connected to the Internet, you must run a "terminal emulation" program and tell that program to connect to the mainframe. The best terminal emulation programs to use emulate IBM 3270 terminals. UNET recommends two: one for Windows called Host Explorer and one for the Macintosh called TN3270. Contact the UNET help desk for information on obtaining these programs.

If you are using a 3270 emulator, you tell it to connect to "host" maine.edu which is the Internet name of the mainframe. When it connects, you will see an opening screen with a big "UMS" in the center and places to enter your UNET account id and password. The screen looks like this (although the colors may vary):

The next section explains the logging on process.

Chapter Top

If necessary, move your cursor to the "USERID" field by pressing your TAB key. Type in your id and jump to the "PASSWORD" field by pressing TAB. Type in your password and press ENTER or Return. The id and password are checked against the CMS password file, and if they match an entry in that file, you are allowed to use CMS.

If you press ENTER or Return after typing in your id and before entering your password, the screen will change, but you will be asked to type in your password anyway. Go ahead and type it in and press return or enter.

If you make a typing mistake, you will be told that the id is "not in the CP directory" or the password is invalid. In that case you can try again, but you don't get the "UMS" screen. Instead type:

    logon nnn

If you continue to make mistakes, you will only be allowed to try three times. Then you must wait for an hour before trying again.

Once your id and password are validated, CMS checks its instructions on how your account is configured (your "directory" entry and "profile") and it shows you your normal CMS screen. If you are a student and this is the first time you have ever logged on to CMS, you will see a "policy agreement" which you must read and say you accept. A copy of this agreement will be stored in your CMS disk space for future reference.

Most accounts will automatically start the "shell" menu system described below. This is because most accounts have a "profile" that invokes the "SHELL" command. You can change your profile if you wish - see the section below entitled Managing your Mainframe Account.

Once you have finished your work on CMS you should always "log off" correctly. Try to avoid simply terminating the connection or quitting your terminal program without going through the logoff procedure. Logging off means informing CMS that you are done, giving it a chance to clean up any open files and do other housekeeping chores.

If you have the "shell" menus showing on your CMS screen, press F3 until you are back at the "Main Folder" and hop your cursor to the very last item "Logoff from system." (See the Shell screenshot below.) Press ENTER (or return) to select that item. You will need to verify by pressing ENTER or return a second time. If you are not using the shell menus, simply type

      logoff

If you don't properly logoff, you may encounter some problems when you try to logon next time (or maybe not). The mainframe may not have "realized" that you went away and will think you are still logged on, or it may "reconnect" you and put you into the CP layer of the operating system (more on CP below). Type "i cms" (without the quotes) and press enter or return to get out of CP and into CMS.

Chapter Top

Here are a couple of images of CMS screens:

Immediately after logging on, you should see a screen similar to one of these. The first one is the screen you get if you use the "Shell" menu system (see below for how to use these menus). The second screen is what you see if you don't automatically start "Shell" when you logon.

Note that there is a "status" indicator in the lower right corner of the second screen image. Most of the time you can ignore that status, but if it reads "CP Read" you may be in trouble! When you see "CP Read" you have dropped into the hardware management layer of the mainframe operating system (see the section on CP below), and need to return to the CMS layer.

Sometimes the "status" may read "Holding" or "More...". In that case, CMS is showing you some important material, but has more to show. It wants you to read the current screen, then give it the "go-ahead" to clear the screen and show you the rest of its material. So keep an eye on that status area.

CMS assumes you have at least 12 F keys and sometimes 24 F keys. It also assumes you have keys labeled PA1, PA2, PA3, Clear, Insert and Delete Character. It assumes you have arrow keys and an ENTER or return key. Microcomputers generally have the arrows and ENTER or return, and often have F keys, but the others may be missing. Look in the documentation on the terminal emulation software you are using to see how to generate these special keys on your keyboard.

CMS applications use the F keys in different ways. Often there is a little guide at the bottom of the CMS screen that says what the F keys do in the current context. For an example, see the "Shell" screen image above. In general, F3 quits whatever is currently going on, F1 gives you the online help and if you are viewing a document that is more than one screen long, F8 scrolls you down one screen and F7 scrolls you back up.

The Clear and PA2 keys can both work to clear the current screen if you see "Holding" or "More..." in the lower right status area. PA1 is used to enter the CP layer (see below), which is usually only done in an emergency (you have written a program and it has gone badly haywire!). CMS doesn't use PA3.

The Insert and Character delete keys are editing keys. Normally in CMS when you want to correct a typing mistake, you move your cursor to the spot and overtype. If you want instead to insert characters, move your cursor to the spot, press the Insert key, and type. Press the Insert key again or press ENTER (or return) to get out of this insert mode. The character delete key simply deletes the character at the cursor.

Moving your cursor around the screen is simple with the arrow keys. The TAB key will also move the cursor down the screen and eventually wrap back around to the top. Many terminal programs also allow you to move the mainframe cursor by clicking the mouse, but this is because of the microcomputer software, not the mainframe. when using these programs, a mouse click looks to the mainframe like lots of arrow presses. The mainframe does not recognize a mouse as such. Because the mouse only moves the cursor, if you are using a menu (such as the shell menu system), you make a menu selection by bringing your cursor to the item you want (by clicking on it, or using arrows or TAB), but then you have to press ENTER or return to tell CMS you want that item. A double-click of the mouse will not work.

Chapter Top

If your CMS account is set up to use Shell automatically, you will see the top level menu (called "Main Folder") as soon as you logon. See the first CMS screenshot above for an example. A CMS account is set up to use Shell by adding the "SHELL" command to the user's PROFILE EXEC file (see Managing your Mainframe Account below for more on the PROFILE).

You select an item from a Shell menu by moving your cursor to that item (use TAB or your arrow keys, or click your mouse), and pressing your ENTER or Return key. Double-clicking your mouse will not work. Your selection may bring you into a lower-level menu or to an actual CMS function such as listing your disk files. Within the menus, the F-key guide at the bottom of the screen tells you how to navigate from menu to menu.

• F3 will move you back to the previous menu unless, of course, you are at the top level already.
• F1 puts you into online help for the shell menu system. If you get into help, press F3 to quit and get back to your menus.
• F2, F4, F5 and F6 are for customizing your menus. You can use F2 to create new "tasks" and F4 to delete any existing menu item. Using these F keys can cause problems - see the CMS troubleshooting page for details.
• F7 and F8 allow you to move through long menus. If you have a menu that is too long to fit on the screen, F8 moves you forward one screen at a time, and F7 moves you back.
• F9 jumps you directly to the top level menu (the "Main Folder").
• F10 create a box in the middle of your screen where you can type a CMS command. Most CMS commands are not represented by Shell menu items. If you want to use those commands you either have to quit the Shell (F12) or use this F10 command box.
• F11 lists the files on your mainframe disk space.
• F12 lets you quit the Shell menus so you are in the normal command environment of CMS. When you quit Shell, your mainframe screen looks more like the second screenshot above.

If you exit Shell (using F12) you must type in CMS commands in order to do work. You can always return to Shell by typing:

      SHELL

Finally, if you select a Shell menu item that performs some mainframe function such as reading mail, when you quit that function (usually by pressing F3) you will be back in Shell. We will discuss the various mainframe functions you can perform by selecting menu items in the sections below.

Chapter Top

IBM has provided complete reference materials on all the standard CMS commands online through the HELP facility. The online help tends to assume that you already know quite a bit about CMS and are using HELP just to refresh your memory.

In general, the F1 key will put you into the HELP system, and F3 will quit. When you are viewing HELP material that is longer than the screen, you can use F8 to move down one screen at a time and F7 to back up towards the beginning. Some of the HELP material is organized in menus, where you can put your cursor on an item and press ENTER or Return to select the item.

The complete set of references for CMS commands is available by typing the CMS command

      HELP

(note that this command is NOT available through a Shell menu - use F10 to bring up a command box in order to type it in.) Here is a screenshot that shows the top level help screen:

Note the F key assignments at the bottom of the screen. These F key assignments are used throughout the help system: F1 shows additional material about the current help topic, if any exists, F2, F5, F7, F8 and F12 are used to navigate within the current help screens, F3 quits the current help material and returns to the preceding screen, F4 returns you all the way out of the help facility.

Some commands are not documented through the standard IBM help system. These are often commands that UNET has added or deal with software installed on the mainframe that is not part of the operating system. To access the online help for these commands, you must type:

      HELP xxxx

where "xxxx" is the command you want to read about. For example, the GETDISK command is non-standard. To read the documentation on this command type:

      HELP GETDISK

Chapter Top

     BEGIN

     IPL CMS

Chapter Top

Your CMS password must be changed at least every 150 days. To change your password, use the account management web page. Please select a password that is 6, 7 or 8 characters long and is a mixture of letters and numbers.

To find out how much disk space you have available, used and free, type the CMS command:

     QUERY LIMITS *

To find out how much central memory you have, type the command:

     QUERY STORAGE

Your PROFILE EXEC file contains commands that are automatically executed when you logon. This is where the "SHELL" command is placed if you want to run the Shell menus everytime you use CMS. If you want to change your PROFILE EXEC file, use the text editor XEDIT to alter this file (for example, if you want to remove the SHELL command). Refer to the next chapter of this document for information on editing files.

The CMS and CP QUERY commands allow you to get various kinds of information about your account. The SET commands let you set some parameters - for example how you use the F keys in CMS. Another command of interest is DIRMAINT which lets you control some settings for your CMS account. Use the HELP system to learn more about these commands.

Using CMS: Contents

Chapter Top

Next Chapter