CMS terminal interface

Overview

CMS (Conversational Monitor System) is an interactive operating system that runs within z/VM. The z/VM system control program provides each user with a virtual machine (that is, an operating environment that appears to be a separate system).

This topic describes the procedures to be followed when connecting to Model 204 through the CMS terminal interface.

Terminals supported

The CMS terminal interface supports the use of:

• IBM 3270 and compatible terminals
• Teletypes and Teletype-compatible terminals

Each of these terminal types provides slightly different capabilities, responses, and default parameter settings. The information supplied for these terminals in Using SNA Communications Server terminals does not necessarily apply when teletypes are used.

Selection of terminal support mode

Two modes of CMS terminal support are available to Model 204 users: multiuser and single-user. To select multiuser mode, the system manager must set the IODEV parameter on the user's parameter line for the terminal. To select single-user mode, the system manager must set the ALTIODEV parameter in the single-user EXEC.

For more information about these system manager actions, see the CMS installation instructions for your operating system. See also Defining the user environment (CCAIN).

Invoking and disconnecting from the CMS terminal interface

The steps required for logging in to Model 204 through the CMS terminal interface and for disconnecting from the CMS terminal interface are described in this section.

Getting online

To connect to Model 204 through CMS, follow these steps:

1. Gain access to CMS by following the z/VM connect procedures defined at the installation. Check with the system manager for specific information. CMS indicates that it has gained control by displaying a ready message.
2. Connect to Model 204 by using M204 EXEC, which formats the Model 204 command. M204 EXEC establishes the environment in which to run Model 204. After this command has been accepted, a prompt is displayed. On the 3270, for example, a greater than sign (>) is displayed.
3. Log in to Model 204 in the usual way, if not already logged in by a command file in M204 EXEC (see the CMD option in M204 EXEC options).

M204 EXEC

The format of the M204 EXEC, as distributed by Rocket Software, is shown below. If an option is not specified, Model 204 provides a default. Defaults can be established for an installation by the system manager, as described in Defining the user environment (CCAIN).

You can obtain more information about M204 EXEC by issuing the HELP 204 command.

Syntax

M204 [(] [LINE | DISPLAY] [USERID userid | CHANNEL channel | DISCONN string | SUBSET string | CMS filename] [LOGIN] [NOLOGIN] [DCSS] [NUCEXT] [UAREA] [ONLINE] [IFDIAL] [VMCF] [)]

M204 EXEC options

The M204 EXEC options have the following meanings:

This option...	Specifies...
LINE or DISPLAY	Mode in which the communication is to be performed. LINE represents line mode and DISPLAY represents full-screen mode. The user can select LINE or DISPLAY, but not both. LINE is the default for all terminals except 3270 terminals; DISPLAY is the default for 3270 terminals. If DISPLAY is the default and a CHANNEL option is not specified, an unsuccessful connection attempt results in an automatic attempt to connect in LINE mode.
USERID userid	User ID of the virtual machine in which the Model 204 program to be accessed is executing. If userid is specified as an asterisk (*), Model 204 is invoked in single-user mode.
CHANNEL channel	Name of the channel (1-8 characters) to which the connection is desired. If the IUCV interface is used, a channel name of M204VMFS must be specified for IODEV 41; a channel name of M204VMIO must be specified for IODEV 39. Note: If the CHANNEL option is used, a mode (either LINE or DISPLAY) also must be specified.
DISCONN string	Character string that is the Model 204 disconnect sequence. If this string is entered, a DISCONNECT command is transmitted to Model 204. The DISCONN option is ignored if Model 204 is invoked in single-user mode.
SUBSET string	Character string that is the CMS SUBSET entry sequence. If this string is entered as the only input data on the screen, the user enters CMS SUBSET mode. In this mode, the user can execute any CMS commands that are nucleus-resident or that load in the Transient Area. For a summary of these commands, refer to the IBM z/VM CMS Command and MACRO Reference. After the user returns from CMS SUBSET mode (by use of the RETURN command in CMS), the subset string is redisplayed on the terminal at the same point the user had entered it. The SUBSET option is ignored if Model 204 is invoked in single-user mode.
CMD filename	Name (1-8 characters) of a user-created file containing commands that are to be read as the initial input to Model 204. The command file must have a file type of M204CMND and reside on a disk accessed by the CMS user's virtual machine.
LOGIN or NOLOGIN	Whether Model 204 automatically generates the initial LOGIN command. LOGIN specifies that Model 204 generate the command. NOLOGIN specifies that Model 204 not generate the command. The user can select LOGIN or NOLOGIN, but not both. LOGIN is the default. The LOGIN/NOLOGIN option is ignored if Model 204 is invoked in single-user mode.
ONLINE or IFDIAL	Connection type for a single user invocation (that is, USER *). ONLINE runs a normal Online connection type; IFDIAL runs an IFDIAL connection type. ONLINE is the default.
VMCF or IUCV	Type of communication used (that is, the VMCF or IUCV interface). Although either VMCF or IUCV can be specified, IUCV communication is always used. Note: In future releases, specifying VMCF might not be supported.

DCSS, NUCEXT, and UAREA specify how the EXEC runs. The meanings of these options are as follows:

This option...	Causes the EXEC to...
DCSS (the default)	Load M204USR, the saved segment version of the CMS or IUCV interface program.
NUCEXT	Load the CMS or IUCV interface program as a nucleus extension. This option is valid only for CMS Release 3 or later.
UAREA	Run the CMS or IUCV interface program by running a module in the user area.

Input lines

Support is provided for two modes of operation: line-at-a-time and full-screen support.

• In line-at-a-time mode, when Model 204 is prepared to accept input, it issues the appropriate prompting character and unlocks the keyboard. After entering an input line, the user indicates that the line is complete and transmits the line by pressing the Enter or Return key.
• In full-screen mode, the user presses Enter to transmit the contents of the entire screen. The full-screen mode of operation is described in Full-screen formatting.

PF keys

Program Function (PF) keys are supported by Model 204 only when the user accesses a screen formatted through the SOUL full-screen formatting feature. Otherwise, PF keys are not supported and cannot be used to enter data. Any line entered by means of a PF key is considered null, and any data entered is lost.

Disconnecting

To disconnect, follow these steps:

1. Log out of Model 204 in the normal way by entering either:

   LOGOUT

   or:

   LOGOFF

   These commands can cause an automatic disconnect to occur.

2. If an automatic disconnect has not occurred, enter:

   DISCONNECT

   or the disconnect sequence for the installation.

CMS displays the Ready message.

Turning off the terminal

If the terminal is turned off during Model 204 processing, subsequent operations depend upon the type of terminal used.

If Model 204 is accessed in full-screen mode, the power-off condition is not detected until the terminal is turned on again. At this point, z/VM forcibly disconnects the user and starts a timer. After 15 minutes, unless the user reconnects to the virtual machine, the user is logged out of Model 204. Model 204 detects the logout and restarts.

If Model 204 is accessed in line-at-a-time mode, z/VM detects the power-off condition immediately, disconnects the user, and starts a timer. After 15 minutes, unless the user reconnects to the virtual machine, the user is logged out of Model 204. Model 204 detects the logout and restarts.

IBM 3270 terminals (IODEV=41, ALTIODEV=47)

This section summarizes the information needed to use IBM 3270s (and compatible terminals) operating in full-screen mode. For full-screen usage in a multiuser environment, the IODEV parameter must be set to 41. For full-screen usage in a single-user environment, the ALTIODEV parameter must be set to 47.

Attention key

The PA1 key serves as the attention key on IBM 3270 terminals, unless the attention key has been reassigned by the user through the FSATTN parameter.

An attention interrupt also can be transmitted by first pressing the RESET key when the keyboard is locked (for example, during request compilation) and then pressing either Enter, PA1, PA2, CLEAR, or any PF key.

Pausing and canceling output

In full-screen mode, Model 204 pauses at the end of each page of output to allow the user to read the contents of the screen or to cancel the current request if too much output is being received.

Valid user responses are.

• Press Enter. The terminal goes on to the next page.
• Press the attention key. Unless an ON ATTENTION statement is in effect (see Attention interrupt feature), the current output and request are canceled.
• Enter a backpage request (see Backpaging).

  Note: The system manager must have set the NBKPG (number of backpages) parameter to allow the user to utilize this feature.

• Enter the next input line.

Screen-formatting parameters

The screen-formatting parameters listed in the following table apply to IBM 3270 terminals used in full-screen mode through CMS.

The PGSEP parameter is not listed because it is not used with IBM 3270 terminals.

Screen-formatting parameters for CMS 3270s

Parameter	Meaning	Default
INMRL	Maximum input line length for terminal	*78
INCCC	Input continuation column	*72
OUTMRL	Maximum output line length for terminal	80
OUTCCC	Output continuation column	80
OUTLPP	Number of lines per page, including headers and trailers	**23
HDRCTL	Page formatting options	0
* Corresponds to single line on screen after prompt and 3270 control characters. ** Last line on screen (24) reserved for end-of-page pause control.

Parameters that describe the physical characteristics of the terminal (INMRL, INCCC, OUTMRL, OUTCCC, OUTLPP) are set automatically when the terminal is logged on. The values of these parameters are set implicitly according to the MODEL parameter setting. See the next section, "Terminal model options," for more information on the MODEL parameter.

Terminal model options

The following table shows the valid settings for MODEL, the corresponding terminal type, and the corresponding default values for the screen size parameters. The user can reset INCCC and OUTCCC to override the default values established by the MODEL parameter.

Valid MODEL settings for CMS 3270s

MODEL	INMRL	INCCC	OUTMRL	OUTCCC	3270 terminal type
1	78	78	80	80	Model 1
2	78	78	80	80	Model 2
3	78	78	80	80	Model 3
4	78	78	80	80	Model 4
5	130	130	132	132	Model 5

Output page buffer settings

MODEL/ is reset only if the size of the output page buffer (LOUTPB) is large enough to hold the new screen size. The minimum LOUTPB settings are listed in the following table.

Minimum LOUTPB settings

MODEL	LOUTPB
0	1170
1	1170
2	2130
3	2770
4	3650
5	3774

Page header formats

HDRCTL consists of a series of switches that control the formatting of pages transmitted to the terminal. Each switch can be set independently of the other.

HDRCTL is usually not reset, but it can be reset to the following values for 3270 terminals:

0	Normal headers (system header showing date, time, and page number)
1	Suppress header 0 (system header showing date, time, and page number)
2	Suppress the blank line that normally follows header 0 for nonrequest output

Handling messages from other terminals

When Model 204 is running in full-screen mode and one user sends a message or a file to another user's terminal using the z/VM facilities, confusion can sometimes result. For example, suppose that user A sends a message to user B's terminal. The z/VM system interrupts user B's Model 204 output and displays the following message at the top of the terminal screen:

14:02:31 MSG FROM OPERATOR: TESTING

The HOLDING message appears in the status area at the bottom right corner of the screen. User B must press the CLEAR or PA2 key to clear the screen and return to Model 204. The remainder of the output is then displayed.

Suppose that user A sends a file to user B's terminal. The z/VM system interrupts user B's Model 204 output and displays a file message, such as the following, at the top of user B's terminal screen:

PUN FILE 4545 FROM MAINT COPY 001 NOHOLD

The MORE... prompt appears in the status area of the screen. At this point, if user B presses Enter, the status area prompt switches to HOLDING; if user B presses Enter again, the prompt switches to MORE... once again. The user must press the CLEAR key to clear the screen. If the user does not press the CLEAR key, the terminal waits 50 seconds, sounds the alarm, waits 10 more seconds, and then clears the screen and continues with Model 204 output.

The system manager can use the Message System Service (*MSG) to control the display of messages on the terminal. See your IBM z/VM system documentation for details.

Teletype terminals (IODEV=39, ALTIODEV=45)

This section summarizes the information needed to use Teletypes and Teletype-compatible devices operating under CMS in line-at-a-time mode. For line-at-a-time usage in a multiuser environment, the IODEV parameter must be set to 39. For line-at-a-time usage in a single-user environment, the ALTIODEV parameter must be set to 45.

Attention key

The BREAK key serves as the attention key on Teletype-compatible terminals. The ATTN key serves as the attention key on IBM 2741 and compatible terminals.

Pausing and canceling output

In line-at-a-time mode, Model 204 pauses at the end of each page of output to allow the user to cancel the current request if too much output is being received.

Valid user responses are:

• Press Return (or any other character) to go on to the next page.
• Press the attention key. Unless an ON ATTENTION statement is in effect (see Attention interrupt feature), the current output and request are canceled.

Parameters

The parameters listed in the following table apply to Teletypes and compatible devices being used through CMS.

Screen-formatting parameters for CMS Teletypes

Parameter	Meaning	Default
INMRL	Maximum input line length for terminal	80
INCCC	Input continuation column	72
OUTMRL	Maximum output line length for terminal	132
OUTCCC	Output continuation column	132
OUTLPP	Number of lines per page, including headers and trailers	56
PGSEP	Number of lines between output pages	2
HDRCTL	Page formatting options	0
TERMOPT	Terminal options	0

These parameters can be reset using the RESET command. The settings of INMRL, INCCC, OUTMRL, and OUTCCC cannot exceed 132. If a larger value is specified, it is automatically changed to 132.

Page header formats

HDRCTL consists of a series of switches that control the formatting of pages transmitted to the terminal. Each switch can be set independently of the others. HDRCTL can be reset to the following values for Teletypes and compatible terminals:

0	Normal headers (system header showing date, time, and page number)
1	Suppress header 0 (system header showing date, time, and page number)
2	Suppress the blank line that normally follows header 0 for nonrequest output
4	Pause at the end of an output page; add a line to each page, in addition to OUTLPP plus PGSEP, to receive a reply.

TERMOPT consists of a series of switches that can be set independently and can be reset to the following values for Teletypes and compatible terminals:

0	Terminal is hard copy (not CRT); no backpaging.
2	Terminal is soft copy (CRT); save and display backpages.

Line-editing characters

When Model 204 is being run in line-at-a-time mode, all the line-editing characters supported by z/VM can be specified. Refer to the IBM z/VM: CMS User's Guide for a summary of these characters.

The following table lists the defaults for the z/VM logical line-editing symbols.

Defaults for z/VM logical line-editing symbols

Symbol	Character	Function
Logical character delete	@	Deletes a character
Logical line end	#	Indicates logical end-of-line to enable multiple logical lines to be entered on a single physical line.
Logical line delete	¢	Deletes a line.
Logical escape	"	Causes z/VM to consider the next character to be a data character, not a line-editing symbol. Used when the input contains a character such as @ or #.

You can define special line-editing characters for a particular virtual machine. Use the z/VM CP QUERY TERMINAL command to determine characters in effect for a virtual machine, and the CP TERMINAL command to change characters. In the following example, the line-end character is reset to slash (/):

CP QUERY TERMINAL LINEND #, LINEDEL ¢, CHARDEL @, ESCAPE " TABCHAR ON CP TERMINAL LINEND /

Model 204 provides its own line-editing characters, defined as parameters, some of which are the same as those used by z/VM.

The following table lists the Model 204 parameters that affect line editing.

Model 204 line-editing parameters

Parameter	Default	Function
ERASE	@	Deletes a character
FLUSH	#	Deletes a line
LINEND	;	Indicates a logical end-of-line

To avoid confusion between the z/VM and Model 204 line-editing characters, the user might want to redefine either the z/VM or Model 204 characters, depending upon whether z/VM or Model 204 is to handle certain types of editing functions.

Note: If identical z/VM and Model 204 symbols are in effect at the same time, unpredictable results can occur.