txzm.doc

这个程序是用于通讯的

                            TXZM -- ZMODEM PROTOCOL DRIVER

               (c) 1991,92 Mike Dumdei, 6 Holly Lane, Texarkana Texas
                        North East Texas DataLink  1:3819/128
                        BBS [phone], Voice [phone]

              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
          commercial 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 7 at any address
               -  Supports simultaneous operation of 2 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 MCOMM551.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 downloaded 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
                  2-7.   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.

          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