dataComet emulator window configurations and text window contents are saved as individual documents which can be launched directly from the Finder. Modeless dialogs make it easy to tailor session configurations for different hosts. dataComet supports AppleEvents, including Internet Config 'GURL' AppleEvents. Command-clicking URLs in dataComet windows launches helpers through Internet Config. Two supporting applications, dataComet-Brown and dataComet-NCSA, are provided to allow Telnet URL launches from Netscape, which does not support Internet Config.
Emulators: dataComet offers multiple VT220, PC-ANSI, and IBM 3278 color terminal emulator windows with searchable scrollback buffers. dataComet is unique in automatically drawing variable-width fonts as mono-spaced fonts; users can set the character height and width of all fonts for maximum legibility. Sessions can be configured so they are automatically logged to a file.
Text Editing: dataComet also offers text editing windows whose contents can be sent to a host by making a selection and pressing the Enter key (or Command-Return to break a line and send it to a host, easing use of host-based Chat programs). Users can use keyed commands to search, move the cursor by characters, words, or lines, and reformat text by adding or removing line breaks.
Printing: dataComet offers both QuickDraw and direct serial printing, so that both WYSIWYG and fast printing are available.
Macros: dataComet includes powerful macro commands which can be invoked through mouse clicks, configurable on-screen buttons, menu items, and key-remapping, and also on host open and close. Macros can be recorded automatically as the user interacts with the host to ease macro creation. An AppleScript interface allows other applications to open dataComet documents, execute dataComet macros, and monitor session status.
Interfaces: dataComet uses an Open-Transport compatible MacTCP interface to support TCP/IP Internet access to host computers, supporting both DEC VT220 Telnet and IBM 3278 TN3270 terminal emulations. Firewalls can be traversed using a SOCKS V4 proxy. Serial access is supported only for the ASCII emulators (serial access to IBM mainframe hosts requires the use of an IBM 7171 or similar VT100 <-> 3278 channel translator at the host end).
File Transfer: dataComet offers X/Y/ZMODEM transfers on both serial and Telnet connections with automatic file launching using Internet Config File Mappings. dataComet also includes a TFTP file server to support TCP/IP file transfer. The dataComet FT3270 protocol is supported for IBM mainframes which have the FT3270 program module installed on the host, allowing transparent downloads for both TCP/IP and serial access. Downloaded files can be printed automatically.
Public Access Terminals: dataComet also supports special configurations for computers intended to be used as public-access terminals, which require enhanced security; a launch macro can be configured which disables commands which are inappropriate for your particular application.
dataComet is fully internationalizable through customization of the on-line documentation and the 'MENU' and 'STR#' resources incorporated in the program. dataComet supports user-configurable international character translation for the Macintosh character set, with character translation tables provided for ISO-Latin-1, DEC Multinational, PC-ANSI, IBM ALA, and IBM 3270.
dataComet uses dataComet documents to retain session configuration information between launches. If you create macros after launching from a document or saving a configuration, they are automatically saved in the document. The "Comet Default" document is a special document which is automatically created in your System Folder when you first launch dataComet. This document contains session configuration data which is used as a default when dataComet is launched by itself or when you use the File menu "New..." command to make a new document, and also contains global configuration data which applies to all sessions. (You can update the "Comet Default" document by saving any dataComet document using "Comet Default" as the name.) If you create a new document by choosing "Reconfigure Session" and changing the name, the new document will have the same settings, macros, and other attributes as the source document. Each new dataComet session requires about 50K of memory.
Note that some functions in dataComet are available only as key macro settings, e.g., disabling cursor positioning for the ASCII terminals. (N.B.: In dataComet you can also disable cursor positioning by using the Macro menu item "Set single-click macro" to cause a single click in the emulator window to do nothing.) Configuring these options in a Connection macro will allow you to permanently configure one of these options for a session.
The "Documents" submenu in the Apple Menu displays the names of the documents available in the "Documents" Folder contained in dataComet's Home Folder. You can add documents to the Folder and they will be included in the list, so you can place frequently-used session documents and other text documents in the folder for convenient access. (This list is only updated when dataComet is launched).
The dataComet Macintosh Telnet/terminal communications package allows you to connect to the two major types of host computer using either a TCP/IP network or serial/modem lines to make the physical connection; dataComet requires Apple's MacTCP TCP/IP driver to make Telnet TCP/IP connections. Using dataComet, you can connect to either an IBM mainframe running an operating system such as VM/CMS or MVS, which uses the EBCDIC character set, or other hosts such as those running an operating system such as UNIX or VMS, which use the ASCII character set.
See the Document "1. Emulators" for more information on the emulators included in dataComet.
dataComet supports character translation tables; see "Translation" in "2. Menus and dialogs". These translation tables use the same format as NCSA Telnet's tables. To add different tables to dataComet you can simply place the document containing the 'taBL' resources in the dataComet "Fonts" Folder before launching dataComet; the new translation tables will be added to those in the menu list. Translation tables are automatically selected when you select a Comet-Font; for other fonts the default character translation is Macintosh <-> ISO-Latin-1 for emulator windows.
You can use "Shift-Paste" to translate from a Macintosh font to the target window's font when Pasting. Other translation features include using the "Translation" command to translate edit window text from the Macintosh character set and back... see "0.1 Shortcuts" and "2. Menus" for more details.
dataComet sessions can use fonts other than the default fonts (Comet ISO Latin-1 for ASCII connections and Comet-ALA for 3270 connections). Proportional fonts are drawn as if they were fixed width fonts so that any font can be used with the emulators. Characters greater than 127 can be displayed in the Comet-ALA font, so that you can use the emulators with alternate fonts and still have the VT100 graphics character set appear correctly. If characters in alternate fonts do not appear as they should, check to see that the "Control Session" dialog item "Don't use Comet-font for characters > 127" is disabled, and make sure you have an 8-bit connection.
A hint for finding foreign characters on the keyboard: To see what character will be produced by a key combination, open the Apple "Key Caps" Desk Accessory, set the font to the font you're using with dataComet, and arrange it on your desktop so it is still visible when dataComet is brought back to the foreground. "Key Caps" will display the characters available while it's in the background. This makes it easy to find various non-intuitive character mappings (e.g., '─' is Option-F when using the Comet font).
See the Document "0.1. Shortcuts" for information on basic keymapping and the numerous mouse click and command key shortcuts available in dataComet and tips for using them. You may want to print out this "0.1. Shortcuts" to use as a reference; if you want to know what function a key command will perform, you can use "Control-Command-key combination" to automatically find any documentation on the Command-key combination.
dataComet offers macros which allow the user to create scripts to execute routine operations automatically. These can be stored as text in an edit window, or associated with a keystroke or other program states... see the document on "Macros" for more information.
dataComet offers an AppleScript interface which allows the user to control dataComet by sending plain text, executing macros, testing connection status, and performing Copy and Paste operations. See the document on "AppleScript" for more information.
dataComet supports scrollback buffers for both 3270 and ASCII emulations which preserve screen character attributes (e.g., inverted or boldface text). Each buffer will grow until memory grows short, at which point the top page of the buffer will be deleted so that new lines can be added. If you want more room for scrollback, use the Finder's "Get Info..." command to increase the size allocated for dataComet. The Edit menu "Clear" command clears the text from the buffer. The Edit menu "Find" and "Find same" commands allow you to search the buffer, and the File menu "Print" command prints either the selection range or the current screen if no selection has been made.
To avoid running into situations where you run out of memory to copy or print, you need to set the scrollback buffer size in the "Control Session..." dialog. Each line scrolled takes three times as much space to store as the length of the line, so 100 lines of an 80-column session takes 24K of memory. To help make sure you don't run out of memory, try to allocate dataComet's memory size in the Finder's "Get Info..." dialog so that when you're running all the sessions you want you have as much memory remaining as the largest buffer you've allocated.
You can open 'TEXT' windows with no associated session by holding down the Shift key when using the File menu "New..." or "Open..." commands or by dropping the documents onto the dataComet application. Edit windows are TextEdit windows, and can hold up to 32K of text.
In addition, each session has a ".edit" window in addition to the window containing the emulator screen. The session name is used as the first part of the window name, with ".edit" added as a suffix. This window is provided for use as a handy text scratchpad and/or scrollback buffer which can be viewed at the same time as the emulator screen; the file contents are loaded automatically when the document is opened.
You can execute macros in edit windows by pressing the Shift-Enter, which causes either the selection or the current line (if no selection has been made) to be executed. See "File Transfer (ZMODEM, TFTP, FT3270)" and "Using the Edit menu" for more information on the .edit window.
When documents are saved, the document's creator ID is changed to dataComet's ID only if the Option key is held down, so that document's default application is usually left unchanged (this is a new default as of dataComet 4.41 to facilitate editing of AppleScript documents).
dataComet supports four different techniques for transferring files: TFTP, ZMODEM, FT3270, and session logging.
ZMODEM is the standard method for tranferring files over serial connections to a host, and offers superior reliability over FTP or TFTP tranfers, since it uses a CRC checksum to help guarantee that data has not been corrupted during the transfer.
dataComet is capable of functioning as a Trivial File Transfer Protocol (TFTP) server, so you can run TFTP on the host to connect to your workstation and transfer files.
A special protocol, "FT3270," was also developed for transferring files over both TN3270 and 7-bit ASCII connections to IBM mainframes. This protocol allows the use of the same user interface for file transfer when the user's computer is connected by either the serial port or a network interface (the current Macintosh version functions only with IBM mainframes with the FT.MODULE installed).
Session logging, which you enable in the File menu, allows you to save lines from your session in a file as they are cleared or scroll off the top.
For more information, see the document "6. File Transfer".
Please note that leaving Control Panels open under System 7 adversely affects performance; this is most noticeable when moving the cursor in a text window, where it causes the cursor to move in a choppy, somewhat sluggish fashion. As more Control Panels are opened, performance is degraded further.
Likewise, if you notice that your Macintosh is performing sluggishly, check to see whether you've left a web browser page open which is running a script. "Cute" pages running scripts which present spinning globes, etc., can degrade performance dramatically even when run in the background. The only cure is to close the browser page or go to another, less cycle-hungry browser page.
Best performance on Telnet links when using MacTCP can be obtained by enabling the "Control Global..." dialog items "Use MacTCP status calls" and "Push MacTCP timers". (This does not apply when Open Transport TCP/IP is being used.)
If it seems that dataComet's interactive response is sluggish over MacTCP (especially over PPP links), you can also select the "Control Global..." dialog "Poll" option to cause dataComet to poll MacTCP to check for new data rather than relying on MacTCP to report new data arrival (which evidently does not always happen promptly with some MacTCP extensions). This will give somewhat better interactive performance, with slower display of long TTY-like listings.
If you wish to make dataComet's screen display updates and scrolling look more like NCSA Telnet's, set the following options:
"Control Global..." ON "Poll"
ON "Use text cursor only"
"Control Emulator..." OFF "Update display promptly on Clear"
OFF "Use VT100 jump scrolling"
Low end Macintoshes such as the Mac Classic and LC series can benefit greatly from having the "Control Global..." dialog item "Enable fast drawing" on. This will cause dataComet to use direct-to-screen drawing routines for 9 and 16 point fonts; if the Monitors Control Panel is set to use Color, dataComet will automatically switch the monitor to Black and White mode and then back to Color mode when you enter and leave the dataComet application. The benefits can be dramatic (for a good example, you might try an LC with a 640 X 480 monitor using the 16 point font when using 3270 emulation). On faster machines with enhanced QuickDraw the difference is less dramatic; this feature is not available on PCI-based PowerPCs, which do not support Black and White mode.
If you run out of memory, try clearing your scrollback buffers using the Edit menu command "Clear buffer", or "Clear" with a small selection to reset the Clipboard.
The fonts dataComet uses for various emulations are included in the "Fonts" folder in the application's home folder. You should drag the font suitcase files into the "Fonts" folder in the System Folder in order to ensure correct results when printing and display of special characters in the Macro dialogs (which use the Comet-Chicago font to display buttons in text fields). It's recommended that first you remove the older versions of the fonts from the System "Fonts" folder, particularly when upgrading from versions prior to 4.43B8, since the font names changed in that release.
Fonts in the current release include:
Comet Chicago
Comet ALA (3270 American Library Association character set)
Comet ALA Bold
Comet DEC-Multinational
Comet DEC-Multinational Bold
Comet Latin-1
Comet Latin-1 Bold
Comet Mona (8 point Macintosh character set)
Comet Mona Bold
Comet PC-ANSI
Comet PC-ANSI-Bold
NOTE that dragging a new version of dataComet into a folder containing an older distribution of dataComet is not recommended, since the fonts may have changed, and the documentation provided has definitely changed! It's better to move documents you use from the old folder to the new folder containing the new distribution.
To configure Netscape to use dataComet, use the Options menu "General Preferences..." dialog to select "Applications." Browse and select dataComet-NCSA as the "Telnet application" and dataComet-Brown as the "TN3270 Application" to use dataComet as the helper application for <telnet://> and <tn3270://> URLs.
Netscape and some other network applications create NCSA Telnet or Brown TN3270 documents and launch them in order to open a Telnet session. dataComet-Brown and dataComet-NCSA (the "dataComet-launchers") automatically translate these documents and launch a dataComet document with the source document configuration (NCSA or Brown) supplemented by the default configuration contained in the "Comet Default" document. If a document already exists, only the host address is updated. These applications also facilitate the conversion of existing NCSA or Brown documents to dataComet documents.
dataComet (and dataComet-NCSA and dataComet-Brown) also support 'GURL' AppleEvents, which allow other applications to notify dataComet that a Telnet session should be opened. When dataComet receives a 'GURL' AppleEvent, it opens a session to the host and places the URL specification in the session's .edit window. If the session has been saved as a document, the document will be opened, so that the configuration and notes made on the connection in the .edit window are retained between sessions.
You can use Internet Config to perform Command-click URL launches from dataComet's windows. This is included in MacOS 8; it is also available from
<ftp://ftp.share.com/pub/internet-configuration/>
Installation of ICeTEe for use with other applications which do not support Internet Config directly is highly recommended.
To configure Internet Config to use dataComet, you can select dataComet as the helper application for "telnet" and "tn3270", since dataComet can handle these directly. However, there are still uses for the launcher applications: you can configure one of them as the Telnet/TN3270 helper application to take advantage of the features described below, and it can also function as a "Set" launcher... see the "Telnet Set example" and "Brown Set example" documents.
The dataComet launchers use the "Comet Default" document to save default configuration settings. You can configure dataComet-NCSA and dataComet-Brown with several different options in the "Control" menu:
"Quit after launching documents": Quit the launcher after opening
documents.
"Make document in source document's folder": Make the new dataComet
document in the same folder as the source document rather than
the launcher's folder.
"Delete source document after conversion": Delete the source
document (should be set as the default when used as a network
helper; WARNING converting existing NCSA documents with this on
will delete them!).
"Overwrite existing dataComet document": Delete any existing
dataComet document rather than re-using saved session
configuration information.
"Delete new dataComet document if not saved": dataComet 4.30 or
higher will prompt the user to delete new documents created
by the launcher when the session is closed (default).
These settings allow you to optimize usage of dataComet when Telnet-surfing with web browsers, so that the configurations of interesting sessions can be retained in between browser-launches, while others are routinely discarded. (SUPPORT EXPERTS NOTE: You can modify the default configuration of these settings for local distributions under a site license by changing the dataComet-NCSA and dataComet-Brown settings on a system with no existing "Comet Default" document. To make these applications sharable, you need to mark them as such using ResEdit.)
Launching preconfigured dataComet documents through Netscape:
If you want to distribute preconfigured dataComet documents to users which will access different applications running on the same host by a web page viewed with Netscape or other web browsers, you should include "login-name@host" specifications in the URLs, e.g., <tn3270://newsroom@ajc.com> or <tn3270://update@ajc.com>, etc. Since dataComet-Brown is used to resolve these names, it will look in the "dataComet-Brown" folder for session documents which already exist (which should be named "newsroom@ajc.com" and "update@ajc.com" respectively).
If you're using Internet Config and have selected dataComet as the "telnet" or "tn3270" helper application, the document should be placed in the "dataComet" home folder.
The Macintosh keyboard layout maps some Option-key combinations into foreign characters. This can cause confusing results when using key macros, so the "dataComet keyboard" keyboard layout is provided to ensure that Option-key combinations are not remapped. You can select this keyboard layout by doing the following: 1) drag and drop the "dataComet keyboard" into the System file in the System Folder and 2) turning on the Control Global dialog item "Remap Option key-combinations". (NOTE: sometimes the installation of this resource into the System by dropping it onto the System file causes partially-corrupt System files to go over the edge to oblivion. If you are using a "foreign" character font, or don't mind Option-key combinations Option-E, I, N, U, and ~, you should leave "Remap Option key-combinations" off.)
