Modern Minds, Inc. - AS/400 Telnet Applet

S/400 Telnet Applet (Version 1.04)

The AS/400 Telnet Applet is a simple telnet terminal emulator that can be used to connect to an IBM AS/400. The terminal emulator can be embedded in a web page, or it can be appear in its own window when the web page is loaded.

equirements

Currently, AS/400 Telnet Applet requires Microsoft Internet Explorer in order to run. This is because Internet Explorer supports signed code (i.e., a signed CAB file) which allows Java to make connections to arbitrary IP address. Once Java 1.1 is in general use, it should be possible to sign code in a generic fashion.

An IBM AS/400 with TCP/IP networking and TCP/IP Connectivity Utilities/400 installed and properly configured is also required.

ecurity Considerations

AS/400 Telnet Applet does NOT provide for secure communications between the applet and the AS/400. The data stream is unencoded and could be intercepted and viewed by anyone who has a basic understanding of TCP/IP protocols.

Do NOT use this applet if you are sending or receiving data that you wish to keep confidential.

peration

There are a number of HTML applet parameters that control how the terminal emulator functions: these parameters are detailed in the Parameters section below. The following is a general description of the applet interface.

The AS/400 Telnet Applet user interface consists of the terminal screen at the top of the applet display area, and controls (some of which are optional) at the bottom of the display area. The standard controls consist of a Connect/Disconnect button and a Reset button. The optional controls are: buttons which emulate function keys F1 through F24; a text field for entering the AS/400 IP address; and a text field for entering the AS/400 port address.

When the applet loads and a connection is established to an AS/400, the function key buttons at the bottom of the display area (if specified) are enabled and the AS/400 sign-on display appears on the terminal screen.

At this point, the terminal session is very similar to a 5250 emulation session and should be fairly familiar to anyone who has used Client Access/400. Please note that the applet is not performing 5250 emulation, but rather a subset of DEC VT-100 emulation. There are a number of significant limitations in the currently implemented emulation: these are listed in the Limitations section below.

Note that the cursor can be positioned on the terminal screen by clicking the mouse button at the location to which the cursor should be moved.

imitations

The F10 and F22 keys are intercepted by the Windows operating system and are not sent to the AS/400. Use the Ctrl-] or a Ctrl-Q to send an F10, and a Ctrl-\ or a Ctrl-W to send an F22.

The Insert key does not toggle the character insert mode in Windows. Use the Ctrl-Delete key instead.

The Input Inhibited and other 5250 indicators cannot be displayed.

Buffered keystrokes cannot be cleared.

ample

If you are using the Microsoft Internet Explorer browser, you can view a web page with an embedded terminal, or view a web page with a floating terminal window.

Be aware that these demonstration pages won't be very interesting unless you know an IP address of a connected AS/400.

arameters

Following are the HTML parameters for the applet. A parameter marked "Opt" is optional, and a parameter marked "Req" is required.

Req	cabbase	The path and name of the CAB file that contains the Java classes.
Opt	host	Initial IP address for host. If this parameter is not specified, then the parameter value defaults to 127.0.0.1 (localhost).
Opt	port	Telnet port address. If this parameter is not specified, then the parameter value defaults to 23 (the standard port number for Telnet).
Opt	emulation	This parameter should be set to "AS400". If this parameter is not specified, then the parameter value defaults to "VT100". Note that the DEC VT-100 emulation is incomplete and may not perform as expected. The VT-100 emulation will work correctly when connected to an AS/400, but you will need to enter VT-100 keystrokes (see the AS/400 Telnet documentation). It's best just to specify "AS400" for the emulation type.
Opt	autoConnect	If set to "true", then the applet will automatically connect to the current host and port whenever it starts (e.g., when the user moves onto the web page). If set to "false", then the connection must be manually started using the applet's Connect button. If this parameter is not specified, then the parameter value defaults to "false".
Opt	idleDisconnect	Number of idle minutes before a connection will be automatically severed. (Idle time is time when no keystrokes are entered.) If this parameter is not specified, then the connection will never be severed due to idle time.
Opt	disconnectOnStop	If set to "true", then an active connection will be automatically ended when the applet is stopped (e.g., when the user moves to another web page). If set to "false", then the connection will be kept open until the browser is shut down or until the user clicks the applet's Disconnect button. If this parameter is not specified, then the parameter value defaults to "false".
Opt	fontSize	Specifies the size of the font used to draw characters on the terminal screen. If this parameter is not specified, then the parameter value defaults to 11 (i.e., an 11 point font is used).
Opt	frameTerminal	If set to "true", then a frame surrounding the terminal screen will be drawn. If this parameter is not specified, then the parameter value defaults to "false".
Opt	floatingWindow	If set to "true", then the applet will be created in its own window. If set to "false", then the applet will be integrated into the web page. If this parameter is not specified, then the parameter value defaults to "false".
Opt	resetKey	Defines the behavior of the applet's Reset button, which becomes active when a connection is established. If the resetKey parameter is specified, then the applet's Reset button is labeled Reset Terminal, and clicking the button causes a defined keystroke to be sent to the host. The resetKey parameter defines the key to send to the host. The first character of the parameter indicates the state of the modifier keys. B (for base) means no modifier keys are pressed, C means that the Control key is down, and S means that the Shift key is down. The Alt key, and combinations of modifier keys, are not supported. Next follows the decimal number of key to send to host. For instance, the applet samples (above) use a resetKey definition of "C10" to send the Ctl-Enter key combination to the AS/400 host (Reset Error). If not specified, then the button will be labeled Reset Connection. Clicking the Reset Connection button will cause the current connection to be severed, then reconnected again.
Opt	displayFKeys	If set to "true", then buttons for the 24 function keys will be displayed at the bottom of the applet. If this parameter is not specified, then the parameter value defaults to "false".
Opt	displayHostFields	If set to "true", then a text field for the host IP address and a text field for the host port number will be displayed at the bottom of the applet. The text fields can be used to specify the telnet host to connect to. If this parameter is set to "false", then the host and port applet parameters should be specified. If this parameter is not specified, then the parameter value defaults to "false".

xample

An example of a HTML APPLET tag with all parameters for the AS/400 Telnet Applet is shown below.

ownload

The AS/400 Telnet Applet class files, along with a copy of this documentation, is available for download as a standard zip file, as a self-extracting file (for Windows95/NT users), or as a self-installing Java class file.

opyright

This documentation and the AS/400 Telnet Applet object code may be copied and distributed freely for non-commercial purposes so long as neither the code nor the documentation is altered in any way. If the AS/400 Telnet Applet code is distributed with any documentation whatsoever, then this unaltered document must accompany the code.

Copyright © 1997, 1998 by Modern Minds, Inc.