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CKOKER.BWR "Beware File" for C-Kermit Version 5A -*- text -*- OS/2 VERSION Applies to version 5A(189) Last update: Fri Jul 16 16:16:28 1993 Authors: Frank da Cruz, Christine M. Gianone, Columbia University. Kai Uwe Rommel, Technische Universitaet Muenchen, Germany. Copyright (C) 1985, 1993, Trustees of Columbia University in the City of New York. The C-Kermit software may not be, in whole or in part, licensed or sold for profit as a software product itself, nor may it be included in or distributed with commercial products or otherwise distributed by commercial concerns to their clients or customers without written permission of the Office of Kermit Development and Distribution, Columbia University. This copyright notice must not be removed, altered, or obscured. Report problems, suggestions, fixes, etc, to Frank da Cruz: Internet: fdc@columbia.edu BITNET/EARN: FDCCU@CUVMA Columbia University Academic Information Systems 612 West 115th Street, New York, NY 10025 USA DOCUMENTATION C-Kermit 5A is documented in the book "Using C-Kermit" by Frank da Cruz and Christine M. Gianone, 1993, Digital Press, Burlington, MA, USA. Digital Press ISBN: 1-55558-108-0; Prentice-Hall ISBN: 0-13-037490-3. Price: US $34.95. In USA, call DECdirect at 1-800-344-4825, refer to order number EY-J896E-DP. A German edition will be available in October 1993 from Verlag Heinz Heise in Hannover, Germany. UPDATE: EDIT 189 As of version 5A(189), OS/2 C-Kermit supports TCP/IP connections if you have TCP/IP installed on your OS/2 system. This requires a change in the installation instructions. A new automatic install procedure is now included, a Rexx program called INSTALL.CMD. Just put the installation diskette into drive A:, click on the Drive A: icon, then click on INSTALL.CMD. To bypass the INSTALL procedure and install OS/2 C-Kermit manually, please read the installation instructions in the READ.ME (CKOAAA.DSK) file. For other new features of edit 189, please read the file CKCKER.UPD. THE 16-BIT AND 32-BIT VERSIONS OS/2 C-Kermit can be built in a 16-bit version, which works under both OS/2 1.x and 2.0 (and later), and in a 32-bit version, which works only under OS/2 2.0 and later. The program herald and the SHOW FEATURES command tell you which version you have. The 16-bit version might run out of stack space and crash under certain conditions (the OS/2 message will be "Stack Overflow"). This is a limitation of the Microsoft C 6.00 development system it was built with, and of the underlying 16-bit architecture. The 32-bit version does not (should not) crash, but it can't be used under OS/2 1.x. So it is best to use the 32-bit version under OS/2 2.00 and later. GENERAL LIMITATIONS AND PROBLEMS C-Kermit does not support multiple sessions. If you SET PORT 1 and make a connection, and escape back and SET PORT 2, the connection on port 1 is closed, dropped, and hung up. To achieve multiple C-Kermit sessions, run separate copies in different OS/2 windows. C-Kermit's performance on serial connections -- and the performance of any other OS/2 communication software program -- can be improved significantly by using a 16550A(FN) communications port controller (UART) rather than a 8250, 16450, or other unbuffered UART. Unbuffered UARTs interrupt the CPU once per character, whereas a buffered UART interrupts every 8-14 characters. Measurements during C-Kermit file transfer on an otherwise unloaded i486/33 under OS/2 2.0 show approximately 60% CPU usage with a buffered UART and 75%-100% using an unbuffered one. And of course, as with all other OS/2 applications (and OS/2 itself), a faster CPU and more memory also help. In any case, native OS/2 serial communications software is NOT as fast as DOS communications software (such as MS-DOS Kermit) under DOS on the same machine because OS/2 communications must be done through the serial device driver, which adds considerable overhead (context switching; registers, stack, call gate, etc), whereas DOS applications access the bare hardware directly. If you refer to a disk drive that is not ready, or to a file on such a disk drive, the OS/2 critical error handler might pop up and require action from the keyboard. This occurs during execution of commands by inferior processes, such as DIRECTORY, REMOTE DIRECTORY, DELETE, REMOTE DELETE, etc. It should not occur in file transfer operations. The "hard error box" will put a halt to unattended, scripted operations, and it stops the operation of the OS/2 C-Kermit server if there is no human in attendance. To work around: add the line "AUTOFAIL=YES" to CONFIG.SYS. This eliminates the hard error box, but it applies system-wide, not just to C-Kermit. You can't give a command like "RECEIVE A:". C-Kermit will fail to open the output file. You must also include a filename, e.g. "RECEIVE A:X.X". Certain commands that rely on underlying CMD.EXE services, including DELETE and TYPE, do not accept full pathnames (or, at least they do not pass them correctly to CMD.EXE). If the PUSH command, and related commands, do not work for you, check the definition of your OS/2 COMSPEC environment variable. There is no way to change the OS/2 code page after you have started Kermit. RUN CHCP doesn't do it because it only affects the CMD.EXE process below, which, of course, exits immediately after running CHCP. Printer support. The good news: . The PRINT command works. . Files can be transferred to PRN in the 32-bit version only. . LOG SESSION PRN works in the 32-bit version. . The Print-Screen key prints the current terminal emulation screen in the 32-bit version (not tested in the 16-bit version). . Host-initiated transparent print operations work correctly in the 32-bit version. The bad news: . There is no Print item in the C-Kermit window menu because C-Kermit is a character-mode (VIO), rather than Presentation Manager (PM), application. . Ctrl-Print-Screen has no effect. . Host-initiated print operations are presently ignored by the 16-bit version (because if they are not ignored, they cause a stack overflow). . The following host-initiated print operations are not supported: - ESC [ 0 i (print current screen) - ESC [ 1 i (print current line) - ESC [ ? 5 i (autoprint is treated like transparent print) . Print operations, when attempted on an OS/2 system that has no printer installed, can hang the Kermit program. Wish list: . Add LAN Manager and other network support. . 132-column mode for VT102 emulator, using horizontal scrolling if the graphics adapter (EGA, VGA) does not support 132 columns. . VT-220/320/420 emulation . Tektronix emulation . Hebrew VT420 features (cursor direction, etc) COMMUNICATIONS AND DIALING Unless you have a very fast machine (say, 25 MHz or higher), OS/2 and its serial port drivers are not fast enough to keep up with serial input at 19200 bps or higher unless you have configured your connection for the optimum type of flow control, preferably RTS/CTS. Symptoms of lost data include fractured terminal screens during CONNECT and packet retransmissions during file transfer. High-speed communication works well if RTS/CTS is effective, but the overall throughput is limited by your PC's CPU speed (and how busy OS/2 is with other concurrent processes). SET LINE and SET PORT are synonyms, they do exactly the same thing: select the communication device. The syntax is the same for both: SET LINE [ <device-name> ] SET PORT [ <device-name> ] If you omit the device name, C-Kermit reverts to its default communications device, normally COM1. If you include a device name: 1. If the device name is a single digit, 1 through 8, C-Kermit converts this digit to the corresponding COM port name, COM1 through COM8. For example, "set port 2" is converted to "set port com2". 2. If the device name begins with an underscore character (_), and all of the following characters are numeric (for example, _12), the number is assumed to be a file descriptor for an already-open communication device (more about this below). If the device name begins with an underscore, but any non-numeric characters follow, a syntax error results. 3. Any other sequence of characters (including "COM1", etc) is accepted literally as a device name. In cases (1) and (3), C-Kermit attempts to open the device, and then, if successful, checks to see whether it is a real communications device. If not, the SET LINE / SET PORT command fails. In case (3) (see below), no checking is done. NOTE: You can also pass an open file descriptor to C-Kermit on the command line, e.g. "ckermit -l 4". See the sample program below. Unless you use the MODE command to change it, the OS/2 serial port device driver requires DSR and CTS. If your modem or device does not provide these signals, you can enable communication by telling the driver not to require them, before starting C-Kermit (or in your CKERMIT.CMD file). For example: MODE COM2 IDSR=OFF,ODSR=OFF,OCTS=OFF If you have problems using COM3, COM4, or higher, specify the address and interrupt number (IRQ) in your OS/2 CONFIG.SYS file, in the line that starts the serial communication driver, COM.SYS (or SIO.SYS): DEVICE=C:\OS2\COM.SYS (number,base-address,irq) ... This example gives the addresses and IRQs for COM3 and COM4 but leaves the values for COM1 and COM2 alone: DEVICE=C:\OS2\COM.SYS (3,3E8,10) (4,2E8,15) and this example gives the values for COM1 through COM4: DEVICE=C:\OS2\COM.SYS (1,3F8,4) (2,2F8,3) (3,3E8,10) (4,2E8,15) WARNING: the addresses and IRQs for COM3 and COM4 are not standardized, and can vary depending on the design and configuration of your communication board. Consult the documentation that came with your communication board. KEY ASSIGNMENTS The default key assignments are as listed in "Using C-Kermit", Table V-3, page 430. DEC PF1-4 to PC F1-4. DEC keypad 0-9 to Alt-0 thru Alt-9, top rank, and so on. If you want to assign these functions to the PC's numeric keypad instead, simply TAKE CKOVTK.INI. SHOW KEY does not show what characters are sent by the special keys F1..F10, Alt-0..Alt-9, or the Arrow keys, nor the actions associated with Page Up, Alt-=, etc. See the Tables V-1..V-3 on pages 428-430 of "Using C-Kermit". SET KEY works with the Num Lock key, but several cautions are necessary: 1. Num Lock has two different scan codes: \510 and \766. 2. Every time you push Num Lock, the scan code toggles. 3. Every time you push Num Lock, the keypad state toggles. Assigning characters to Num Lock with SET KEY does not change this behavior. Thus, if you want the keypad keys to always send the same codes, no matter what the Num Lock state is, you must include two SET KEY commands for each key. This is done by CKOVTK.INI. If you need to send VT220 key sequences (F6-F20, Help, Do, Find, etc), use the VT220 section of CKOVTK.INI. Read the comments in the second half of the file for directions to find out how to activate the VT220 key settings, and, if using a VAX/VMS host, give it these commands before starting your application: $ set term /device=vt200 $ set term /noeight Key scan codes are not all the same as in MS-DOS Kermit. Most ordinary keys have the same codes, but not as many keys are differentiated. All combinations of Ctrl, Shift, and Alt with a particular key do not necessarily produce unique scan codes. There are no \Kverbs as in MS-DOS Kermit. TERMINAL EMULATION SET DEBUG SESSION is currently not supported. Various VT102 terminal features are not supported, including: . Blink . Smooth scroll . Switching between 80- and 132-column mode and others are simulated: . Double-width and double-height lines (by doubling characters) . Underlining (by a distinct color) Scrolling is slower in an OS/2 Window. This is because OS/2 is operating in graphics mode and must draw each dot (pixel) individually. Fullscreen scrolling is faster, which uses character mode. But when running C-Kermit in fullscreen you lose the ability to cut and paste. The cursor disappears briefly while the screen is being updated and appears again within a few milliseconds after screen activity stops. This can be somewhat disconcerting, but it increases the speed of screen updates. SET FLOW XON/XOFF prevents you from transmitting Ctrl-S and Ctrl-Q characters to the host. These characters are commands (Search and Quote) in EMACS. If the host sends the escape sequence to put the terminal into 132-column mode, and subsequently sends data that would appear in the rightmost 52 columns, this may interfere with existing data on the screen. If C-Kermit is started in an OS/2 132-column fullscreen session under OS/2 2.0 (only possible on certain video adapters), it will display such data correctly but will always be in 132-column mode, even if only 80-column mode is used. Shift-in/Shift-Out works only if you SET TERMINAL LOCKING-SHIFT ON. FILE TRANSFER There is no way send the complete contents of a file in text mode if the file contains a Ctrl-Z character that is not the last character in the file. In other words, Ctrl-Z is always treated as end-of-file when the FILE TYPE is set to TEXT. There should be a SET EOF {CTRLZ, NOCTRLZ} command as in MS-DOS Kermit to control the treatment of Ctrl-Z characters in text files. Be sure to activate the appropriate type of flow control before transferring files, especially if you are using long packets: SET FLOW RTS/CTS Preferred, if the device your PC is immediately connected to supports it. SET FLOW XON/XOFF Used end-to-end, but subject to noise corruption, propogation delays, etc. By default OS/2 C-Kermit uses whatever flow control is already configured for the communications port driver at the time you started C-Kermit.