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Text File | 1994-10-02 | 27.2 KB | 516 lines

TXZM -- ZMODEM PROTOCOL DRIVER (c) 1991-94 Mike Dumdei, 6 Holly Lane, Texarkana Texas North East Texas DataLink 1:3819/128 BBS (903)838-6713, Voice (903)838-8307 TXZM (Texas Zmodem :) is a zmodem protocol that was developed to demonstrate the speed and capabilities of the MCOMM C serial communications library. The latest version of TXZM or MCOMM may be obtained from N.E.T. DataLink by either logging in and downloading or by file request of "MCOMM" or "TXZM". The shareware version of MCOMM contains the TXZM shell in source form and the low level Zmodem driver in library form. The complete source code comes with the "Libs & Source" registered version of MCOMM. Libraries for all memory models except for the BCC/TC huge model come with the "Libs Only" registered version of MCOMM. See the MCOMM order form for specifics on various options. TXZM RESTRICTIONS TXZM IS NOT PUBLIC DOMAIN however the executable version may be distributed and used free of charge for non-commercial purposes. If you intend to use TXZM commercially or in a com- mercial environment and the program will be loaded or operated on more than 3 systems ANYWHERE within the organization, you must obtain a license. The complete TXZM source code is provided as part of the "Libs & Source" registered version of the MCOMM software package. Linkable libraries are provided with the "Libs Only" registered version of MCOMM. None of the source code or libraries that are part of the registered version of MCOMM may be distributed, neither may they be incorporated in whole or in part into a competing software product without a written license agreement. Competing software products are products that are not end user programs themselves, such as "Your Serial Library", and products that directly compete with TXZM (fully developed terminal programs, BBS systems, and similar products are FUNCTIONALLY DIFFERENT than TXZM and NOT considered competing products). The license agreement requirement for commercial use of the EXECUTABLE VERSION ONLY (TXZM.EXE) does not apply to governmental, educational, church, civic, or non-profit organizations. This does not waive restrictions that apply to the source code for those organizations. MCOMM ASYNC LIBRARY (Advertisement) MCOMM is a serial communications library for Microsoft C, Turbo C/C++, Borland C/C++, and Zortech C/C++. It also will work with any other C compiler or language that supports Microsoft C calling conventions. Some of the features of MCOMM are: - Fully interrupt driven - 16550 FIFO mode support - Baud rates up to 115200 baud - Supports definitions for any comm port that operates on IRQs 2 through 15 at any address - Supports simultaneous operation of 4 ports - Written in assembler for maximum speed and minimum code size - Advanced features such as block transmit and receive, XON/XOFF and hardware flow control, receive buffer look ahead, definable ring buffer sizes and location, ... Also included with MCOMM is a set of ANSI capable video functions that support windowed output, save/restore screen functions, timer functions, and miscellaneous other code. The current shareware version of MCOMM is MCOMM600.ZIP. It includes a complete small model LIB, TXZM (partial source, rest as libs), and both a C and C++ demo terminal program. The registered version is available as either "Libs only" or "Libs & Source". The "Libs Only" version is $25 and includes libraries for all memory models. The "Libs & Source" version is $45 and comes with both libraries and all source code. See the MCOMM order form. TXZM OPERATION TXZM has 3 modes of operation. These are command line send, command line receive, and terminal mode. Running TXZM with no command line parameters will list available TXZM options. Specifying the serial port: TXZM directly supports COM1 through COM4, however COM3 and COM4 on older hardware may not match what is considered standard. The -c switch (described below) may be used for non-standard configurations of COM3 and COM4 or to force TXZM to recognize a custom port. For standard versions of COM1-4, use "txzm com#" where '#' is 1-4. TXZM switches: -u Start in terminal mode. Terminal mode may be started either before or after a CONNECT is made. It has a limited set of functions (dial, upload, download). -r Start in receive mode. This switch must come last on the command line if it is used. It may be followed by an optional subdirectory if the files are to down- loaded to a specific location. The -r switch may be used in conjunction with the -u switch to specify a download directory. When used with the -u switch, TXZM starts in mini-terminal mode. -s Start up in send mode. This must be the last switch on the command line and be followed by the filename(s) to be sent. The filename list may contain wild cards. The send function will recurs subdirectories if the filename specifications are placed in parenthesis. Placing filenames in parenthesis to recurs subdirectories also works in mini-terminal mode. -p Send or accept complete pathnames. This option, used in conjunction with the -r option, will cause TXZM to accept complete pathname information in the received filename. Without it, only the root name and extension of the filename are used. If the received filename specifies a directory that does not exist, it will be created. If a download directory was specified (-r dlpath), the subdirectories will be created under "dlpath". When used with the -s switch, the -p switch will cause filenames to be sent with complete path information. Per zmodem specifications, only the path is sent (no drive identifiers). Without the -p switch only the file's root name and extension are sent. This applies even if recursing subdirectories. -b#### Specify the CONNECT baud rate. The CONNECT baud rate is used to determine estimated file transfer times. TXZM currently will not adjust to a CONNECT rate when initially making the connection. Unless a locked baud rate is used (-l), you must dial using the baud rate you will CONNECT at. If the connection is already established, and neither -l or -b is given, TXZM will open the port using the baud rate it is currently operating at. -l#### Set a locked baud rate. Use this option to set a fixed computer to modem baud rate. The -b option may be used with the -l option to specify both the computer to modem rate and the modem to line rate. -chhh,# Specify a non-standard port configuration. TXZM will work with any port addresfrom 000h to 3f8h and IRQs 2-15. Replace 'hhh' with the port address in hex and '#'ith the IRQ to be used. For example, to use a port at I/O address 2E8h that uses IRQ 5, use "txzm -c2E8,5". -h Use hardware flow control (RTS/CTS). This is required for modems that use a locked baud rate. -i Ignore absence of carrier detect signal. Use this switch when using TXZM to transfer files between systems connected with a null modem cable. (TXZM only requires the Rx, Tx, and Gnd wires to be connected). -v Disable serial I/O during disk writes. Use this option if errors occur when the received data is written to disk. This should only be necessary when operating at high baud rates with no 16550 UART or the file is being downloaded to a floppy. The -v option also expands the disk buffer to 20K bytes to maintain a higher level of efficiency. -e# Set duplicate file handling option. This option determines what happens if an attempt is made to download a file that already exists. The following choices are available: -e0 Skip the file -- do not download. -e1 Resume the transfer at the end of current file. This is the default. -e2 Create a duplicate file name and download the file as a separate file. -e3 Overwrite the existing file. -w#### Sets the maximum bytes that may be in transit at any one time (transmit window size). This must be a multiple of 128. -x Escape all control characters. This option causes the characters between 00h and 20h, 80h and A0h, 7Fh, & FFh to be ZDLE escaped. Zmodem automatically escapes XON, XOFF, ZDLE (CAN), DLE, and "<CR>@<CR>" sequences. The -x option is for networks that do not pass other control characters. -x# As an option, a specific list of control characters to escape may be given. For example to only ZDLE escape the ESC character (27 decimal or 1B hex) and ESC+parity (145 decimal or 9B hex) and let all other control characters pass unaltered, use: -x27,145. -6 Force use of 16 bit CRC. The default is 32 bit CRC. This option does not show up on the help screen (ran out of room). -7 Strip high bit from received characters in terminal mode. -0 Use BIOS screen writes. This only works in command line mode. Mini-terminal still does direct writes. -q Run in DesqView mode. This option makes TXZM DesqView aware meaning it writes to DesqView's video buffer rather straight into video memory. It also causes TXZM to release its time slice when it is idle. -y Added in version 2.25. Allows overriding the received filename on Zmodem receives. Ex: txzm -y THISNAME.ZIP -r The above line would cause the received file to be called "THISNAME.ZIP" rather than the name sent by the sender. This option does not show on the help screen. -$ Added in version 2.30. Sets "quiet mode" when doing file transfers. With this option set, the display of the zmodem transfer screen and transfer stats are disabled. This option does not show on the help screen. 16550 related switches: -d Do not enable 16550 FIFO mode. Normally TXZM automatically enables FIFO mode. If you are using a Western Digital 16550 UART at lower baud rates you may need to use this option. The WDC16550 UART doesn't work in FIFO mode at low baud rates. If you have a 16550 and don't know if it is a Western Digital but get Garbled Packet errors when attempting to start a transfer, try this option. The National Semiconductor 16550 (NS16550A) works at all baud rates in FIFO mode. -t# Maximum characters to send to 16550 FIFOs per interrupt. This may be between 1 and 16. The default is 8. A lower value may be required for modems that used a locked baud rate, hardware flow control, and have a small internal buffer. 8 works fine with USRs. -m Disable modem status register interrupts. This option is another patch to accommodate Western Digital's version of the 16550. Some WDC16550s lock up if the modem status lines (CTS, CD, etc.) are not connected to a driving signal. This could happen if the serial or null modem cable being used does not have all signal lines connected (very possible with a null modem cable). Using -m prevents this problem. It also disables hardware flow control and carrier detect, however, so if you require either of these and have a WDC16550 you must use a cable with all appropriate lines connected. Examples: txzm -p -s (c:\) // send all files on drive C -- include // complete path information txzm -p -r // accept complete pathnames -- if path // does not exist, create it txzm -p -r d:\temp // accept complete pathnames but put files // and created directories under D:\TEMP txzm -r // receive to current directory, if path // information is received it is ignored txzm -s (\project\*.c) (\project\*.h) // Sends all .c and .h // files in the subdir PROJECT and all subs // under project. Does not send pathnames. txzm -u -r \dnlds // start in mini-terminal mode, received // files are placed in "\dnlds" directory txzm com2 -u // mini-terminal mode, use COM2 txzm -l38400 -b9600 -h -s file1.zip file2.zip // 38400 baud locked rate, 9600 CONNECT, // hardware handshake, send file list txzm -b2400 -u // 2400 baud, mini-terminal mode txzm -c2e0,15 -r // custom serial port at 2E0h on IRQ15, // use current baud rate, receive txzm com2 -b115200 i u // 115200 baud, ignore carrier detect, // mini-terminal mode txzm -e2 -r // COM1, current baud rate, receive, create // duplicate name if file exists txzm -s @filelist // send all files listed in "filelist" // the name "filelist" is an example only Other than the -r and -s switches that must appear last on the command line if used, neither case nor switch order are significant. Also you may use a '/' instead of a '-' or no switch identifier at all. Ex: "txzm i E2 -u /b2400 r" is legal syntax. GENERAL NOTES TXZM is faster than any other zmodem protocol driver I am aware of. It will run at 95% efficiency in both send and receive modes at 115200 baud on an 8 MHz 286 with a 16550 UART. This translates to an effective throughput of 110 Kbps. In a PC Magazine (Apr 91) article reviewing various communications software packages, the BEST zmodem operated at less than 50 Kbps when tested at 115200 baud on the same type of equipment (8 Mhz 286's with 16550 UARTs). TXZM is over twice as fast. The review covered several well known shareware and commercial packages. TXZM was also tested on a 4.77 MHz 8088 laptop that contained the functional equivalent of a 16450 UART (no FIFOs) and a 4.77 MHz IBM XT (true blue IBM) that had 16550 UARTs installed. On the laptop system TXZM could send most efficiently at 23040 baud and receive most efficiently at 28800 baud. The XT, with 16550 UARTs, could receive at a full 38400 baud but with the baud rate set to 38400 could only achieve an effective throughput rate of around 35000 baud. The tests were performed using the systems' hard drives (original slow hard drives), not a RAM disk, which also had some impact on speed. With 16550 UART's, TXZM could very effectively work a high speed modem (HST, V.32, or V.32bis) even on a slow 4.77 MHz computer. If you compare the CPS rating stated by TXZM and other programs, you may find TXZM reporting slightly lower rates. This is due to a difference in the calculation method TXZM uses only. Many other progams appear to fudge a little bit on their statistics. At lower speeds or on fast CPUs all Zmodem drivers will run about the same. The speed difference shows up when the system is under a load such as with extremely high baud rates or moderately high baud rates on slow CPUs. BBS SUPPORT TXZM now recognizes the TXZMLOG environment variable and will create a log file with the same format as the one created by DSZ if DSZLOG is set. This was added primarily to support BBS software that uses DSZLOG format log files to track downloads, efficiency, etc. If all you want is a log file you can set TXZMLOG only. If you are using BBS software that looks for a DSZLOG variable, you will have to also set DSZLOG to the same value as TXZMLOG. Ex: set TXZMLOG=C:\BBS\ZMODEM.LOG set DSZLOG=C:\BBS\ZMODEM.LOG I did not use DSZLOG to avoid infringing on any non-public domain features of DSZ. If you want to patch your personal copy of TXZM to use DSZLOG directly rather than TXZMLOG, you can use a utility such as Norton Utilities or PC Tools to scan TXZM.EXE for the string "TXZMLOG" and change it to "DSZLOG". This is only patch you are authorized to make. DO NOT under ANY circumstances distribute ANY modified version. It is also now possible to specify a file that contains a list of the files to be sent. This is also primarily for BBS support. To use this option precede the file containing the list of files with an '@' sign. The files may be separated by any valid whitespace characters including spaces, tabs, carriage returns, line feeds, etc. The -q option has been added as of version 2.10 for BBS operators who run under DesqView. It causes TXZM to not mess up the video and also to release CPU time when it is waiting for characters or for the transmit buffer to empty. The -0 option will disable direct screen writes if you are using command line send or command line receive options. All screen writes will be done through BIOS calls. Mini-terminal mode does direct writes even with the -0 option specified. -0 does not appear on the help screen. BBS sysops may also use TXZM free (even if you charge for access to your system). REVISION HISTORY 2.41 Working version of 2.40b below. IRQs 8-15 now work. So do the fixes for Delphi. 2.40b Released only as a limited beta version and can cause problems. Added support for IRQs 8-15 (but it didn't work). Some of these are used by the system software so make sure to pick a free one. Made two changes to the core functions to enable zmodem uploads to the Delphi information service to work properly. 2.31 Some early PCI motherboards (mine, for instance) use a chip set that causes the serial port to lock up when FIFO mode is enabled. 2.31 detects this problem and unlocks the port (transparent to the user). Also changed dial function so it will recognize "CARRIER" as a valid connect string. 2.30 Finalized version of the 2.26b. Also 1) modified the routine that captures the CONNECT rate so that it works with the higher speed modems (V.FAST), 2) added a "quiet mode" of operation (see -$ flag) that disables the zmodem transfer display screen, and 3) added the ability to specify a modem init string and the dial prefix string via the TXZMDIAL.DIR. See TXZMDIAL.DIR for more information. 2.26b Added an optional dialing directory for miniterm mode. The dialing directory is an ASCII text file (you create) that TXZM looks for when the program first loads (see TXZMDIAL.DIR for an example of how to set up the directory). Also changed the CPS calculation routine to make it display correctly when running under DesqView. (THIS IS A BETA VERSION). 2.25 Fixed the "-c" (custom comport switch). Added -y (override received filename) switch. 2.24 Fixed a problem with the "recurse subdirectories" option and also corrected a problem that caused TXZM to not work right when running it in a DOS box under OS/2. 2.22 Recompiled using a different version of the MCOMM communications driver. 2.21 Fixed a divide by zero error that occasionally occurred on restarted file transfers. 2.20 Added support for Doorway mode (ALT = toggles it on and off). Added support for BBSs that autodetect ANSI capable programs. Added -7 switch to enable stripping high bit when in terminal mode. 2.14 Minor changes so code will compile without warnings using BC++ 3.0 and so that TXZM would automatically trigger a Qmodem download (Qmodem requires an "rz\r" as well as the INIT packet -- most programs trip on the INIT packet alone). Also modified the -n (BBS support option) so that it took the name of a Maximus or Opus style LASTUSER.BBS filename rather than a node number. Modified FIFO usage so that TXZM set FIFO buffers to 1 in terminal mode and 8 when sending files (corrects jerky display at low baud rates). 2.10 Changed name to TXZM from ZMP. The ZMPLOG environment variable is now TXZMLOG. Found out somebody else already had a ZMP in CP/M days. Added DesqView aware option. Fixed Dial Command so that it looked at the connect baud rate and adjusted accordingly. Fixed Redial Command to continually dial until a connect was made or ESC pressed. Added F1 for help key. Added ALT-P so the modem parameters could be changed manually, ALT-C so the screen could be cleared, and ALT-= for Doorway mode operation. 2.00 First non-beta version. Added a capture file. Fixed a minor problem with the -0 option. 1.21 Added support for specifying files to send in a file that contains a list of the filenames. Added -0 option (disable direct screen writes in command mode). 1.20 Fixed bug introduced in version 1.19 that caused a divide by zero error if the total bytes to be sent was between 1 and 18. Added ZMPLOG environment variable. 1.19 Corrected bugs in the -w and -x options. Fixed problem with negative CPS rates showing up when more than 11 megabytes were sent. Added the -6 switch. 1.17 Fixed double backslash in pathnames when downloading while in the root directory (couldn't DL to root). 1.16 Added support for send and receive of complete pathnames and creation of subdirectories. This allows duplication of entire drives or subdirectories through the serial port. 1.10 16 bit CRC mode now really does work. TXZM102 was supposed to have fixed it but didn't. 1.02 Fixed bug in 16 bit CRC mode (I thought). Fixed minor error in ZRPOS handler. The sender now sends a ZCRCW packet when an error occurs rather than a ZCRCG. This conforms with Chuck Forsberg's Zmodem specification. 1.01 Fixed bug in ZRPOS handler. This bug occasionally caused TXZM to trash the screen and lock up when a ZRPOS was received. Optimized the code. TXZM will now operate at 115200 baud at 95% efficiency on an 8MHz 286 (approx 11100 cps -- 2 meg in 3 mins). A 16550 UART is required to obtain high speed operation. In mini-term mode, PGDN puts TXZM in receive mode in case the sender's ZRQINIT was missed. Previously it relied on the incoming ZRQINIT to trigger receive mode. It now works either way. Added a '-v' switch. This switch disables overlaying disk and serial I/O. It also expands the receive file buffer to 20K bytes. The result is 20K of data is received, serial I/O pauses, the 20K is written to disk, a ZACK is sent, and the sender resumes sending.