Compatibility: This version of dataComet has been tested with various models of the Macintosh, and is likely to work with models from the Mac+ to the Quadra and PowerPC 9500 running Systems from 6.0.3 to 7.5.1. This version will work on the Mac+ and other systems running older versions of the Mac System, but you may experience problems.
Menu-key equivalents are superseded by macro keys, but the menus are not corrected.
The Print command, when QuickDraw printing is used, does not space characters correctly when the dataComet-fonts are used to print foreign language characters, and will not use the dataComet-fonts with Background Printing unless they are installed in the System.
Some Macintosh configurations (such as those using an E-Machines display board) may "hang" soon after dataComet opens its first session windows if fast drawing mode is enabled. This occurs due to incompatibility between the display adapter and the fast drawing mode. To fix this problem, you can reconfigure your "Comet Default" document by launching dataComet, cancelling the initial Configure Session dialog, turning off "Enable fast drawing" in the Control Global... dialog, and pressing the OK button. (Another method is to throw out the "Comet Default" document in the System Folder.)
If you try to download a file to a locked disk, after the file transfer fails you will not be able to access that particular file again until you quit and restart dataComet; you will not be able to completely dismount the disk because the file will be "busy", although you can eject the disk, unlock it, and access other files.
Nota Bene: The MacTCP driver interface can have asynchronous sends enabled; in this mode, Macs using MacTCP up to 1.0.2 on LocalTalk will be prone to crash (with the cursor frozen and the whole machine hung). You can configure this option in the Global Configuration dialog. MacTCP 1.1.1 works properly when asynchronous sends are enabled.
Those using Ethernet should enable asynchronous sends, because there is a major drawback to using synchronous sends: until the host acknowledges that it has received the data you have sent, the Mac will seem to "hang." Although the mouse cursor will move, the Mac will not respond to mouse button-downs or keystrokes until the acknowledgment is received; in the event of a communications problem with the host, this can leave you hanging for minutes! If this occurs, you should NOT reboot your Mac, but should wait for the send to either complete or abort.
(In general, it is desirable to have asynchronous MacTCP sends enabled, and to have the fast-drawing option enabled; due to the possibility of encountering the rather lethal problems discussed above, these options are disabled in the default configuration.)
In general users experiencing crashes when using MacTCP on an Ethernet are suffering from the presence of a dysfunctional 'ENET' resource in the System. Installing the most recent version of the Apple Networking software usually fixes such problems.
E.g., some versions of the Asante drivers have been unreliable when used with MacTCP, resulting in seemingly-random crashes. These often occur due to conflicts with MacTCP, which cause MacTCP to call a debugger trap (which crashes your machine if you have no debugger installed!) If you are using an Asante Ethernet device, you should install the Apple Networking software using the Installer on your System disks.
dataComet 4.1.2A appears to work correctly with Open Transport on the 9500. Comet 3.1.3 does not.
OT as of 1.0.7 does not support the MacTCP Status call which is supposed to report statistics. By default, dataComet no longer uses these calls; a Control Global option has been added to enable this for non-OT machines.
OT 1.0.5B4 has a bug which causes it to report the Maximum Segment Size incorrectly, which caused dataComet to fail when attempting to create a session. dataComet 4.1.4A has been modified to handle this problem.
Several versions of MacTCP are available; unfortunately, none of them works properly on all machines (except perhaps 2.0.4, we shall see...). Herewith are the advantages and drawbacks of each:
2.0.6: Seems to be about the same as 2.0.4 with dataComet, although it seems more prone to hang than 2.0.4 when performing Fetch FTP transfers.
2.0.4: Finally a version of MacTCP which seems to have most of its problems fixed. The packet retransmit timeout behavior has improved, but you may want to configure dataComet to lower the Resend Time Out by default, since the 1-second floor seems quite high for an interactive Telnet session.
2.0.2: Apple has worked some on the problem with resending lost packets too slowly, however it is not fixed.
1.1.1: Apple strongly advises that 1.1.1 be used with System 7.1; however, 1.1 seems to work OK as long as Virtual Memory is off. This version fixes several bugs in previous versions: e.g., it displays the LocalTalk icon properly in the Control Panel, does not crash on the Mac+, and apparently handles asynchronous sends correctly . Unfortunately, it waits from 3 to 15 seconds to resend a lost packet, which can make it unusable with ASCII hosts on networks with high rates of packet loss.
dataComet does NOT try to fix MacTCP's resend behavior by default. You can enable this behavior by using the macro "!tD". You can display MacTCP's resend timers by using the macro "!CD"; you might want to take a look at this if you've been having trouble with SLIP.
1.1: Required for System 7 up to 7.1. This version crashes on the Mac+. The LocalTalk icon does not always appear in the MacTCP control panel when LocalTalk is the selected Network device.
1.0.2: A special version of MacTCP 1.0.1 released to improve the performance of MacX. This version is known to cause crashes on some machines.
1.0.1: The first functional release version of MacTCP. Asynchronous sends under LocalTalk are definitely hazardous with this release, resulting in machines hanging with the cursor frozen. 1.0.1 works under System 7, but only if Virtual Memory is off and a copy or alias is placed in the System Folder so that Domain Name Resolution will work properly. Using 1.0.1 with System 7 is not recommended.
System 7.0 notes:
The Macintosh Toolbox routine which Comet uses to draw color text perform very slowly with non-white backgrounds under System 7.0.
* Text windows. Using "New..." or "Open..." with the Shift key held down opens a document as a connectionless text-only document. This is a TextEdit document which has a 32K size limit.
* GUI improvements. The Control Controls... dialog allows the user to configure the dataComet emulator window controls to suit individual preferences. The "About dataComet" menu brings up a text window containing the text. Documentation is contained in separate text files rather than within the application.
* Selectable Fonts. You can now select fonts other than the dataComet fonts. ASCII emulators support the display of proportional fonts as well as fixed point fonts.
* PC-ANSI support with 8 colors. This will be fixed soon to support 16 colors and sizes other than 9 pt. will be available in the dataComet-ANSI.SYS Font.
* VT100 support now includes Print Streaming and the display of blinking and double-width and double-height characters. The dataComet fonts are automatically switched in for the display of characters > 127 when a different font is in use; this can be disabled in the Control Emulator dialog. Scrolling through the scrollback buffer is now much faster than it was in Comet.
* If the Control Global dialog item "Enable Fast Drawing" is enabled and a session with the correct font/size is launched with Color mapping off, dataComet changes the Monitor mode to black-and-white automatically.
* The Control "Printing..." dialog allows the use of non-QuickDraw serial printers which are connected to the Printer Port. Sessions can be configured to print all text off the top of the page automatically.
* Enhanced text commands. "Undo" is now supported in edit windows, and the Edit menu "Selection" submenu offers commands for cursor motion, bracket matching, and text quoting.
* Macros: "Record actions for macro" now has a delay built in so that the user no longer has to type slowly for the recording algorithm to work well. The "Define key macro..." dialog now offers "Ignore Caps Lock" (so that the Caps Lock key is ignored when matching key macros) and "Use Command Font" (so that the user can use the whole emulator font rather than the special command font which reinterprets ASCII characters > 127 and uses them as command buttons). "Dump key macros" now formats the macros in a nicer fashion.
* The "Control Emulator" dialog for the 3270 now offers a new paste option which puts the pasted text into the same starting position as the first line pasted.
* The "Control Session" dialog now allows you to set the Tab Threshold which is used when copying and the Edit menu item "Table mode for Copy and Save" is enabled.
Bug fixes:
* The 3270 now handles an EUA command correctly in all cases; this could cause fields not to be erased correctly if the previous field was protected.
* Failed MacTCP close calls no longer cause crashes.
* MacTCP receive buffers are now allocated to be (4 * MTU + 1K) with a 16K minimum so that dataComet performs better.
* dataComet works on the Macintosh 9500 under Open Transport. For some reason OT failed when dataComet allocated large send buffers.
* The "Add page numbers at bottom of page" and "Add line feed after carriage return" were switched in the "Control Printing" dialog.
* When windows are closed, the corresponding Window menu entry is disabled. Selecting a closed but not-disabled window caused crashes.
* When "Show status bar at the top of the window" is disabled, the labels associated with the Macro status rectangle are no longer displayed. This caused crashes if the window was closed with the go-away box.
* The Telnet Send menu item "Break" now sends a Telnet Break rather than a Telnet Interrupt Process.
* The buttons at the top and left of the screen can now be associated with macros by holding down the Option key while clicking on them.
Bug fixes:
* The screen erase and scroll rectangle is now set correctly when a session is opened with a font size other than 9 pt. This caused seriously muddled screens!
* Menus are now set correctly for the document which is frontmost. Sometimes the menus were set up for a text document rather than a session document and vice-versa.
* dataComet no longer registers an NBP name on AppleTalk network.
* When a text documents which is already open is opened again, the document is brought to the front rather than being opened again.
* Text document window positions are now saved correctly.
* Open Transport 1.0.5b4 reports an overlarge maximum segment size on Ethernet which caused dataComet to fail when creating a session. Sessions will now open even though the segment size is reported incorrectly.
* When new documents are closed, the user is prompted to save them.
* "Option-Resize Window" now resizes the emulator screen and negotiates a Window Size (NAWS) Telnet option with Telnet hosts.
* Pasting a sound resource ('snd ') into a dataComet window sets the window's beep to the sound and saves the resource automatically.
Bug fixes:
* The "Control Emulator" item "Answerback" now sets the Answerback message for ASCII emulators.
* Button macros are now always posted to the correct session when they are executed.
* When text windows are saved, the changed flag is set so that the user is not prompted unnecessarily when quitting dataComet.
* The "!W>windowname\000" macro now works more reliably. Text windows now discard macro keys which can't be sent out on a connection, so connectionless text windows won't fail to post macros after a macro containing characters for a connection is executed. (This makes text windows more useful for running macros.)
* Font sizes equal to zero are presumed to need a 9-pt font. (Some helper applications produced NCSA documents which passed on an invalid font size to dataComet-NCSA.)
* Windows have a minimum window size enforced so that scrollbars and old Comet documents with bad window sizes will display correctly.
* Control Global items have been added to control MacTCP status calls and optimization of the MacTCP resend timers.
* dataComet 4.1.6A now works with OT. MacTCP (especially when emulated by OT) intermittently fails to notify applications that data is available. dataComet used to use MacTCP status calls to check this; it now works around this problem by occasionally performing a Read without notification. (You can tell when this is happening because of a lag in typing input...)
* Old Comet documents which did not contain a Print Layout resource sometimes crashed when opened.
* The notification window for sessions which have the status bar disabled is now retained between calls to ensure that it will be there if memory is low. This could cause a crash.
* The labels displayed by the "?" control are now aligned properly.
* The "Map Return to Newline" item in the "Control Ascii Emulator" dialog has been replaced by two items are used to set the mapping, "Return key sends [] CR followed by [] LF". If "Map Return to Newline" was true, it's taken to mean that return -> CR LF.
Bug fixes:
* MacTCP Read calls now rely on asynchronous completion routines rather than the MacTCP Notification routine. This enhances performance by replacing the kluge used in 4.1.6A for OT compatibility of occasionally performing a Read (which required 1 second to complete when no data was available) to catch the cases where the Notification routine failed to report data arrival correctly.
* The selection scrolls properly now when the top of the buffer scrolls beyond the maximum scrollback buffer limit. When a copy is attempted the selection range is tested for being out of range and an error is reported if it is.
* Undo resizes the scroll bars correctly.
* The ASCII emulator drawing routines sometimes left lines blank which should have been drawn if the line was inverted and the line before it had blanks at the end.
* VT100 character deletion now shifts the on-screen image a double rather than single width when characters are double-wide.
* The VT100 PF4 key now works correctly (it was sometimes mapped to the cursor right key).
* Command-key combinations which don't match menu items are now ignored.
* To prevent confusion and possible mangling of macros, the key macro dialog item "Use Command Font" is disabled while a macro is being edited.
* The Single-click macro is now interpreted if one has been set.
* Labels for the macro buttons are now updated correctly and saved when the titles are changed.
* The documentation on Macros was incomplete in 4.1.6A; it has now been updated to include more information.
