Usenet 1994 January/usenetsourcesnewsgroupsinfomagicjanuary1994.iso/sources/misc/volume1/8709/alex/2

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Path: uunet!seismo!sundc!pitstop!sun!amdcad!ames!ll-xn!husc6!spdcc!m2c!necntc!ncoast!allbery
From: [e-mail] (Kenneth Van Camp -FSAC-)
Newsgroups: comp.sources.misc
Subject: ALEX part 2/2 (MS-DOS library exchange program)
Message-ID: <[e-mail]>
Date: 29 Sep 87 20:28:05 GMT
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Approved: [e-mail]
X-Archive: comp.sources.misc/8709/alex/2

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# -rw-r--r--   1 allbery  System     33251 Sep 29 16:11 alex.doc
# -rw-r--r--   1 allbery  System      1644 Sep 29 16:11 undigest.c
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X        ALEX USER'S GUIDE (VERSION 1.2)
X        ===============================
X
X    Alex [Automatic Library EXchange] is a program that allows
Xautomatic transfer of groups of files (either ASCII or binary) via
Xelectronic mail. Some assumptions are made in the discussion below:
X  o  You are using the Msg (mmdf) or Mailx electronic mail systems.
X  o  Alex has already been installed on your Unix system.
X  o  You are able to log in to the electronic mail system from your
X     personal computer (PC), using communications software.
X  o  Your communications software supports the Kermit file transfer
X     protocol. This is definitely true if you are using the public
X     domain Kermit program, and may or may not be true if you are
X     using a commercial communications program. Note that the
X     popular Crosstalk XVI (running on the IBM PC, Wyse PC and
X     compatibles) DOES support the Kermit file transfer protocol.
X     Also note that Syterm, which is used widely here at ARDEC, does
X     NOT support Kermit and therefore cannot be used in conjunction
X     with Alex.
X
X    This user's guide explains everything you need to know to be
Xable to use Alex. It goes through the steps in excruciating detail,
Xand more advanced users may want to skip some of the discussion.
XFor these people, I recommend skipping the download discussion
Xbecause it is very simple (and explained in much shorter terms in the
Xman page -- type 'man alex' on your Unix system). They may proceed
Xdirectly to the section on Uploading.
X    Keep in mind that this documentation details the use of Alex
Xunder BOTH Msg and Mailx.  These are two different electronic mail
Xprograms in use at ARDEC.  If you are using Msg, please ignore all
Xreferences to Mailx.  Of course, if you are using Mailx, ignore all
Xreferences to Msg.
X
XUSING ALEX TO DOWNLOAD:
X    If you receive a library of files that was sent from someone else
Xusing Alex, you must use Alex to download the files to your PC.  The
Xdiscussion below assumes you are using one of the U.S.  Army electronic mail
Xsystems, Msg or Mailx; instructions on other mail systems may vary.
X    When you are in Msg or Mailx and get a message telling you that an
XAlex-encoded library has been sent, the first thing you must do is
Xdetermine the message number of the library. Usually, the sender will
Xsend you two messages: a cover letter and the library. Since they are
Xusually sent in rapid succession, chances are good that the library
Ximmediately follows the cover letter in your mailbox. To be certain,
Xhowever, you should print out the headers of all your messages. To do
Xthis in Msg, type the letter 'h' (the word 'headers' will appear),
Xfollowed by the letter 'a' (the word 'all' will appear), followed by
Xa carriage return.  To print out the headers in Mailx, just type 'h'.
X    When you see the list of headers, you should look for the
Xlibrary. It usually has the same subject header and sender as the
Xcover letter. Note the message number to the left of the library
Xmessage.
X    Msg users may now type the letter 'l' (the word 'list' will appear),
Xfollowed by the message number you just noted, and a carriage return.  Msg
Xshould respond with:
X    To file/pipe:
XWhen you get this prompt, you should type:
X    | alex
XNote that the vertical bar in the line above is called a 'pipe symbol',
Xand is not to be confused with the letter 'l' or the number '1'. It is
Xa unique symbol which you should be able to locate somewhere on your
Xcomputer keyboard. Follow this line with a carriage return.
X    Mailx users can accomplish the same thing by typing
X'|<message #> alex' (without the quotes).  For instance:  |2 alex
Xwill pipe message number 2 to Alex.
X    At this point, you have invoked Alex.  After a pause (not usually
Xmore than 30 seconds), you will get more information from Alex.  First,
Xyou will see a message similar to the following:
X
X    The following files are ready for downloading.
X    Times given are estimated transmission times, in minutes, to send files
X    to your PC.  If you are directly connected to the Sytek cable network,
X    use the T9600 numbers.  If you are using a 1200 baud modem, use T1200.
X    If you are using a 4800 baud modem, use T4800, etc.
X
X     Filename            Size    T1200  T2400  T4800  T9600
X     ======================================================
X     ed.def                97      0.0    0.0    0.0    0.0
X     ed.dir              1642      0.5    0.2    0.1    0.1
X     ed.exe             98644     27.4   13.7    6.9    3.4
X     ed.hlp             50522     14.0    7.0    3.5    1.8
X     ed.spc               784      0.2    0.1    0.1    0.0
X     ed.trs              1837      0.5    0.3    0.1    0.1
X     getyn.com             97      0.0    0.0    0.0    0.0
X     go.bat                12      0.0    0.0    0.0    0.0
X     order               1147      0.3    0.2    0.1    0.0
X     pcwmouse.def        2514      0.7    0.3    0.2    0.1
X     pcwmouse.doc         874      0.2    0.1    0.1    0.0
X     pcwmouse.msc        4575      1.3    0.6    0.3    0.2
X     pr.exe             45656     12.7    6.3    3.2    1.6
X     quicks.me            962      0.3    0.1    0.1    0.0
X     read.me             1503      0.4    0.2    0.1    0.1
X     story               1148      0.3    0.2    0.1    0.0
X     workdisk.bat        3278      0.9    0.5    0.2    0.1
X     ------------------------------------------------------
X     total             215292     59.8   29.9   15.0    7.5
X
XIn this example, 17 files had been sent in the Alex library and were now
Xready for transmission to the user's PC.  The first column of the table
Xlists the names of all the files.  The second lists the file sizes, in bytes
X(the number of characters in the file, approximately).  The last four
Xcolumns are just to help you estimate how long it will take to transmit all
Xthe files to your PC.  These times are listed in minutes, and are the result
Xof a simple calculation based on something called a "baud rate", or
Xtransmission rate.  Only one of these last four columns applies to you,
Xdepending on what baud rate your PC is operating at.  If you are operating
Xat 9600 baud, then you should look at the column labeled "T9600".  If you
Xare operating at 1200 baud, then look at the column marked "T1200", etc.  If
Xyou are unsure, then chances are you are probably operating at 9600 baud.
X(This is the standard rate used on the ARDEC Sytek cable network.)
X    At the bottom of the table is the total number of bytes of all
Xthe files, and their estimated total transmission times.  This will tell
Xyou roughly how long your PC will be tied up while the files are
Xtransmitted.  Keep in mind that this is just an estimate, and that actual
Xtimes will vary (by as much as a factor of 2).
X    Finally, after the table, you will see this message:
X
X    In a moment, you will see a few meaningless characters at the bottom
X    of your screen. When this happens, start up the Receive Kermit on your PC.
X
X    Now you are ready to begin receiving the files that Alex is ready to
Xtransmit.  To do this, you must tell your PC to begin receiving files using a
Xprotocol known as "Kermit".  The actual process of starting up the Receive
XKermit depends upon the communications software you are using.  Here are
Xinstructions for doing this on a couple of the popular software packages.
XIf you do not have one of these, please consult your communications software
Xdocumentation or your system guru, or send mail to <msdos-request@ARDEC> and
Xwe will try to help you.
X
X            CROSSTALK XVI USERS
X            ===================
X    If you are using Crosstalk XVI, starting up Receive Kermit is
Xeasy. The first key you must press is known as the 'Attention' key.
XWhen Crosstalk is sold, the 'Attention' key is defined to be the
X<Esc> key. However, it is possible to redefine this key to be virtually
Xanything on your keyboard. This is commonly done with Unix users, since
Xthe <Esc> key is required for other purposes. A common way to redefine
Xthe 'Attention' key is as <PgUp> (on the numeric keypad). The actual
Xkey set on your version is shown at the lower left corner of your screen
Xwhen Crosstalk is invoked. For instance, it might say 'PgUp for ATtention'
Xif the <PgUp> key is to be used.
X    Whatever your 'Attention' key is, press it. Crosstalk should
Xthen ask for your Command on the bottom line of the screen (the bright
Xline -- also called the Status line). You should type in the letters RK
X(short for Receive Kermit) and a carriage return.
X    The rest is automatic. Crosstalk should respond by placing a
Xsmall rectangular box at the bottom of the screen that shows the status
Xof the file transfers. If more than one file existed in the library, you
Xwill get a new box for each file. When the file transfer is complete,
Xyou will have copies of all the files on the disk of your PC. (If you
Xuse subdirectories, the files will be in the same directory as Crosstalk.)
XYou will be automatically returned to communications with the Unix system
Xcomputer when the transfer is complete.  You will be back in Msg or Mailx
Xwhere you left off.
X
X            KERMIT USERS
X            ============
X    If you are using the public domain Kermit program on the IBM PC,
XWyse PC, or compatible, the instructions for starting up the Receive
XKermit are as follows. First, you must hit the "escape character" on your
Xversion of Kermit.  Note that this is NOT usually the key marked <ESC>
Xon your keyboard.  "Escape character" is probably a poor choice of words,
Xbut that's what they call it.  It is probably better called the Attention
Xcharacter, like Crosstalk calls it.  At any rate, the "Escape character" in
XKermit is usually defined to be <Ctrl>] (hold the Control key down and
Xstrike the right-bracket key at the same time).  It may be defined
Xdifferently on your version, but this seems to be fairly rare.  (If you want
Xto be sure, just look at the status line at the bottom of your screen.  At
Xthe left it probably reads:
X  Esc-chr: ^]
Xand some other things after that.  The ^] is just a shorthand notation for
X<Ctrl>].
X    After you hit <Ctrl>] (or whatever your escape character is),
Xthe status line at the bottom of your screen should disappear. Now type
Xthe letter 'c', and you should receive the prompt:
X    Kermit-MS>
XNow type in the word 'receive' (minus the quote marks, of course) and
Xhit a carriage return. Your screen will clear and be replaced by a status
Xscreen that shows how the transfers are progressing and the names of the
Xfiles transferred.  When the transfer is complete (which may take a while,
Xdepending on the size of the library), you will hear a beep and be returned
Xto the Kermit-MS> prompt.  Now you should type the letter 'c', followed by a
Xcarriage return.  You will be back in Msg or Mailx where you left off.
X
X                ALL USERS
X                =========
X    Now that you have received all the files in the library, you can
Xdelete the messages in your mailbox.  Use the 'd' command to accomplish
Xthis.
X
X
X            UPLOADING USING ALEX
X            ====================
X    Once you have become familiar with the use of Alex, you may wish
Xto submit some of your favorite programs to the msdos library, or to send
Xlibraries of files to other users. We will call this process 'uploading'.
XWhat you have to do to upload is create an electronic mail message for
Xsomeone else that is in a format compatible with Alex. Doing this is
Xquite easy, using the Alex Upload option. In contrast to the normal use
Xof Alex to download files, the upload option should not be executed from
Xwithin Msg. Rather, it should be called from the shell (the $ prompt in
XUnix). At the $ prompt, just type:
X    alex -u
XYou will receive a message from Alex confirming that you have selected the
XUpload option, and then requesting information for the electronic mailer
X(who you want to send the library to, who will get carbon copies, and a
Xsubject or brief description).  Then you will be presented with a menu of
Xoptions for sending a cover letter.  A cover letter is just a message that
Xis sent out to the person (or people) to whom you are sending the Alex
Xlibrary, which explains how to get the library to their PC.  It is sent in
Xa separate message from the library, immediately before the library.  The
Xintent is that the person on the other end will read the cover letter before
Xhe ever sees the Alex library (which is pretty much unreadable, and will
Xconfuse anybody if they just get it alone).  Here is the menu you'll see:
X
XA cover letter may be sent separate from your Alex library.
XYour options are:
X  (1) Send no cover letter.
X  (2) Send standard Alex instruction file.
X  (3) Send your own cover letter that you have already saved in a file
X  (4) Edit the standard cover letter.
XType 1, 2, 3 or 4:
X
X    Option 1 is self-explanatory.  Option 2 allows you to send a
Xstandard message that has been made up beforehand.  It gives good
Xinstructions for downloading Alex libraries to an IBM PC or other
XMSDOS computer, for users of either Msg or Mailx, using either Crosstalk
Xor Kermit communications programs.  If the person you are sending the
XAlex library to fits this description, then you're probably best off
Xjust using the standard cover letter.  If you want to see what the
Xstandard cover letter looks like, use Option 4.  Option 3 allows you
Xto send a cover letter that you have already composed and saved in a
Xfile.  If you select this option, you will next be queried for the name
Xof the file.  Option 4 lets you edit the standard cover letter, using any
Xeditor you like.  This command will allow you to add some comments to
Xthe standard cover letter, like an explanation of what you're sending and
Xwhy.  The way Option 4 works is as follows: If you know your way around
XUnix pretty well, you probably know what an "environment variable" is.  If
Xyou don't know what an environment variable is, then just skip the rest of
Xthis paragraph because it doesn't pertain to you and isn't necessary.  Alex
Xchecks to see if the environment variable EDITOR exists, and if so, uses the
Xeditor specified in that variable for editing the standard cover letter.
XThe actual command executed is: $EDITOR /tmp/inst$$ where /tmp/inst$$ is
Xjust the name of a temporary file where Alex stores the standard cover
Xletter.
X    If no EDITOR environment variable exists, Alex asks you for the
Xname of your favorite editor.  If you use 'vi', then just type in 'vi'
X(minus the quotes).  If you use jove, type that in, etc.  Muse or
XWordmarc composer should work as well, but you will have to be sure
Xto save the file in ASCII mode.  When the cover letter is complete, you will
Xget the message:
X    Please start up the Send Kermit on your PC (XK in Crosstalk).
X    This process is very similar to the one described above for starting
Xup the Receive Kermit.  Crosstalk users beware, however: Crosstalk must be
Xin the 'binary mode' before you start sending any files.  See the note at
Xthe end of this section on 'binary mode' transfers if you are using
XCrosstalk.
X    In Crosstalk, you must hit the ATtention key, and this time type XK.
XYou will then be prompted for the name of the file you wish to transmit.
XYou should type in the full filename of the first file you need to send.
X"Wildcards" are permitted, so for instance to send all files on the A: drive
Xyou could type in  A:*.* for the filename.
X    In Kermit, you should hit the <Ctrl>] followed by a 'c', as before.
XThen at the Kermit-MS> prompt you should type 'send flnm' where flnm is the
Xfilename of the first file you need to send.  Again, wildcards are permitted.
XHowever, Kermit has an advantage over Crosstalk that it also allows you to
Xsend files from a different directory from the one you are currently in.
XYou can do this by changing the "working directory" with the CWD command at
Xthe Kermit-MS> prompt.  For instance, if you have a directory named
X"PUBLIC", you can make that your working directory by typing CWD \PUBLIC
X    In Kermit, you should be careful to quickly reconnect (the letter
X'c' and return) after your sending is completed; otherwise you will miss
Xthe next message from Alex. In Crosstalk, you needn't worry about this
Xbecause you are automatically reconnected. Alex will then respond:
X    Do you want to send more files (y/n)?
X    If you have additional files to include in this library, you should
Xtype the letter 'y' (upper or lower case) and return.  If this is the only
Xfile you are sending, type 'n'.  This process will continue until you have
Xsent all the files you need to send.
X    When you have finished sending all the files, Alex will mail your
Xcover letter and then your library to the address you specified earlier.
X
X            BINARY MODE IN CROSSTALK
X            ========================
X    As was mentioned earlier, Crosstalk users must put Crosstalk in
X'binary mode' prior to starting up the XK command for uploading. There
Xare two ways to do this, depending on your level of expertise. The easiest
Xway is as follows: Any time after starting up Crosstalk and before you
Xstart up the Alex transfer, you should hit your ATtention key and then type:
X   kermit mode binary
Xfollowed by a carriage return. You need only type this once, each time you
Xstart up Crosstalk. The option will then remain in effect until you leave
XCrosstalk, and will not affect other operations.
X    If you don't want to bother typing this in every time, and if you're
Xhandy with MSDOS files, you can make it automatic so Crosstalk is ALWAYS
Xset to 'binary mode'. All you have to do is create a short 'script' file
Xfor Crosstalk with the following line in it:
X    kermit mode binary
XA script file is any file, in the Crosstalk directory of your disk, that
Xends in a .XTS extension. Furthermore, the first part of the filename should
Xbe the same as your setup file. So if you have saved your setup under the
Xname 'CABLE', for instance, then Crosstalk has saved a file in your
Xdirectory called 'CABLE.XTK'. Your one-line script file should then be
Xcalled 'CABLE.XTS'. Then, if you start up Crosstalk by typing 'XTALK CABLE'
Xyour script file will automatically be executed (putting you in binary
Xmode), your setup file will be read, and you will be automatically into
Xthe communications mode of Crosstalk.
X    In case you are not familiar with any file editors in MSDOS, the
Xfollowing commands, typed at the DOS level, will create the file CABLE.XTS:
XCOPY CON CABLE.XTS
XKERMIT MODE BINARY
X^Z
X(where ^Z denotes a CTRL-Z; hold down the control button and press Z at the
Xsame time).
X
X           UPLOADING WITHOUT ELECTRONIC MAIL
X           =================================
X    On occasion, you may wish to upload an Alex-format library but
Xkeep it in a file on the Unix system computer, instead of sending it out
Xby electronic mail. (This is necessary for the msdos librarian, who
Xkeeps the archives on the Vax.) The format for accomplishing this is
Xsimple. Instead of just typing:  alex -u
Xyou should type:
X    alex -u libname
Xwhere libname is the name you want to assign to the file that will be
Xcreated. Instructions for the use of this option are the same as above,
Xexcept that mailing instructions will not be generated.
X
X                THE TAC OPTION
X                ==============
X    Users of the Picatinny TAC will be happy to know that the latest
Xversion of Alex contains special support for the TAC.  If you don't know
Xwhat the TAC is, skip this section.  You don't need it.
X    Ordinarily, Alex uses all the default options of Unix Kermit
X(90 byte packets, no parity, and eight data bits).  However, this is not
Xcompatible with the TAC, and thanks to the work of Jim McCoy we have found
Xthe best combination for Kermit to work on the TAC: 40 byte packets, even
Xparity, and seven data bits.  If you use the TAC option of Alex, these
Xparameters will be used.  Selecting the TAC option is easy.  For downloading
Xfiles from Msg, just use the command:
X    | alex -tac
XIn Mailx, use:
X    |<message #> alex -tac
XFor more details on packet lengths, parity, and data bits, see the Kermit
Xmanual (type 'man kermit').
X
X            THE LISTING OPTIONS
X            ===================
X    If you have been sent an Alex library and want to know what files
Xit contains, you have two options.  One is to pipe the message to:
X    | alex -q
XThis gives a quick listing of all the files in a library, with a notation
Xas to whether the file is ASCII or binary.  If you also want to know the
Xlengths of the files, you have to use the "long listing" option:
X    | alex -l
XThis option takes considerably longer than the quick listing, but produces
Xa table just like the one issued before downloading.  It gives the size
Xof each file, and estimated transmission times at different baud rates.
XThe reason it takes so much longer to produce is that the entire library
Xhas to be decoded to produce it; the quick listing just checks picks the
Xfile names from the encoded library and prints them out, unadorned.
X
X            ADVANCED FEATURES OF ALEX
X            =========================
X    The remainder of this document is for advanced users only, and
Xneed not be read by the average user of Alex.  The options detailed below
Xshould not be used by anyone who does not have a thorough understanding
Xof file formats and the ASCII codes.
X    There are three advanced options available in Alex.  The first is
Xthe ASCII option (-a).  This option is provided for users who wish to
Xupload plain text files and send them out in a form that is readable on
Xthe Unix system.  This option is not necessary for the average user, since
Xplain text files are automatically treated properly by Alex for transfer
Xbetween PC's.  It is only provided for advanced users who wish to be able
Xto read their Alex libraries on the Unix system.  The effect of choosing
Xthis option in Upload mode is that files are received in Kermit's non-image
Xmode (as opposed to Alex's default, which is to upload everything in image
X-- or binary -- mode).  They are not compressed or encoded, as normal Alex
Xlibraries are.  Instead, they just have an extra line prepended identifying
Xthe file as ASCII and giving the file name.  On downloading, Alex checks
Xeach file for this header line and, if it exists, merely strips off the
Xheader and sends the file in non-image mode, without decoding or
Xuncompressing.  Since each file is checked individually, you can even
Xconstruct an Alex library that contains a mixture of ASCII and binary files.
X(Note that since specifying -a for an upload makes all files ASCII in that
XAlex run, Alex cannot itself create libraries with a mixture of ASCII and
Xbinary files.  You have to do the uploads separately to create two
Xlibraries, then merge them with a text editor.)  Alex ignores the -a
Xparameter in download mode.
X    The second advanced option is the decode option (-d).  This is
Xa "low-level" command to decode an Alex library (from standard input)
Xand leave the files in the user's current directory.  This command is
Xsimilar to the download option, except that no file transfers are done.
XIt should be noted that text files which originated on a PC will be
Xunreadable on the Unix system, unless they were uploaded with the ASCII
Xoption.  The decode option may not be used in conjunction with any other
XAlex options.
X    The third option is the encode option (-e), which is the inverse
Xfunction of decode.  The user specifies (on the command line) all the files
X(on the Unix system) that he wishes to encode together into an Alex library.
XThe files are put together into an Alex library, and the result send to
Xstandard output.  It is the responsibility of the user to redirect this
Xoutput to a file, for example:
X
Xalex -e foo1 foo2 > foo.lib
X
Xto create an Alex library from the files foo1 and foo2, and call it foo.lib.
XThe encode option may not be used in conjunction with any other Alex options
Xexcept ASCII.
X    The fourth option is the list option (-l), which merely generates
Xfor the user a listing of all files in an Alex library.  (The library is
Xsupplied on the standard input.)
X
X            POSSIBLE PROBLEMS WITH ALEX
X            ===========================
X    If the three advanced options mentioned above are not used, there
Xis very little that can go wrong with an Alex transfer.  About the only
Xthings that go wrong for the average user is the communications.  A Kermit
Xtransfer may be aborted for any number of reasons, and in this case the
Xonly thing to do is try again.  If problems recur, there is probably very
Xlittle Alex (or its author) can do to help you; you have to straighten out
Xyour communications problems before any Alex transfers can be attempted.
XSee the Kermit manual for more information, or send a message to the msdos
Xmaillist to solicit help from other users.
X    Another possible cause of problems is the mailer.  These problems
Xrarely occur, but a file could be corrupted (or only partially mailed)
Xwhen being mailed between different computers.  In this case, you will
Xsee a message:
X
Xbad format or Csum to atob
X
XThe offending file (or files) will be left as zero-length files, and
Xthe rest will be downloaded normally.
X    If the advanced features of Alex are used (especially the ASCII
Xoption), then there is additional potential for problems.  Since files
Xare not encoded, it is possible to confuse Undigest (the program that
Xbreaks up the Alex library into its constituent files).  Undigest works
Xby breaking up files at the occurence of any line that begins with at
Xleast six dashes in a row.  Therefore, any ASCII files that happen to
Xhave a line beginning with six dashes will be improperly broken.  If
Xthis happens, the file you get with that file's name will contain
Xeverything before the first line with six dashes.  The remainder will
Xbe treated by Alex as an encoded file.  When Alex attempts to decode it,
Xyou will get the same error message mentioned above ("bad format or Csum
Xto atob") and the information will be completely lost.
X    The Encode and Decode options can also cause some problems, but
Xnot as serious.  If you encode normal text files on the Unix system, NOT
Xusing the ASCII option, and then someone attempts to download them to a
XPC, the resulting files will NOT look normal.  This results from a subtle
Xdifference between the ways Unix and MSDOS store text files.  In MSDOS,
Xthe end of a line is demarked by both a Carriage Return (CR) and a Line
XFeed (LF) code.  In Unix, just an LF alone is used.  In MSDOS, a CR makes
Xthe cursor return to the first column of the screen when TYPEing a file,
Xand the LF moves the cursor to a new line.  In Unix, the LF alone is
Xsufficient to move the cursor to the first column AND to a new line.
XTherefore, if a Unix text file is printed on an MSDOS screen, the result
Xis that the cursor never returns to the first column, and lines do not
Xlook right.  Conversely, if an MSDOS text file is printed on a Unix screen,
Xall the output appears double-spaced.
X    If this is so, then how come you can use your PC as a terminal and
X'cat' files from Unix, and they look alright?  The answer is that your
Xcommunications software (Crosstalk, or Kermit, or whatever) is translating
Xthese codes for you, converting the Unix LF's to CR/LF pairs and only
Xsending a single CR when you hit the return button.  (Unix will actually
Xaccept EITHER a CR or LF to mark the end of a line.)
X    And given all of this, how come it is still possible to download
Xa text file in Kermit non-image mode, and it looks fine on your PC screen?
XThe answer to this is that Kermit is translating these codes for you.
XEvery time you send a file from a Unix system to an MSDOS system through
XKermit (non-image mode), Kermit changes all the LF's to CR/LF pairs.
XAnd every time you send a file from an MSDOS system to a Unix system,
XKermit changes all the CR/LF pairs to LF's.  This is one of the differences
Xbetween Kermit image and non-image modes; in image mode Kermit does not
Xmake this conversion.
X    The moral to all this is that you cannot encode Unix text files in Alex
Xnon-ASCII mode if you intend to send them to a PC.  Conversely, you cannot
Xdecode MSDOS text files that were uploaded in Alex non-ASCII mode if you intend
Xto read them on the Unix system.  This is a good part of the reason why
Xthe Encode and Decode options were labeled "advanced commands"; you must
Xbe very conscious of the tradeoffs and pitfalls involved.
X
X            ALEX IMPLEMENTATION
X            ===================
X    This section explains how Alex was implemented, and the format
Xof the files it creates.
X    Alex was written on a DEC Vax 11/780 running Unix 4.2 BSD.  Making
XAlex run on another Unix system should be fairly simple.  You only need
Xcompile the 'C' programs undigest.c, btoa.c, atob.c and compress.c and put
Xthem somewhere in your path.  This can be done by:
X    cc -O -o undigest undigest.c
X    cc -O -o btoa btoa.c
X    cc -O -o atob atob.c
X    cc -O -o compress.c
X    ln compress uncompress
Xassuming that you have already created the files undigest.c, btoa.c, atob.c
Xand compress.c.
X    One note on the Btoa and Atob programs. The copies of these programs
Xthat I am sending out with the Alex source files is my own version of the
Xpopular public domain programs of the same name. However, I have slightly
Xmodified these programs to add a minor option. I won't go into details here,
Xbut the main point is that my version is completely compatible with the old
XBtoa and Atob programs; but the old ones won't work with Alex.
X    The only other thing you must do is make a small modification to the
XAlex shell script file. Near the top of the file (immediately following the
Xcomments) you should see a line assigning a value to a variable called
X'mailer'. You should change this line so that the name of the mail
Xprogram on your system is assigned here. For instance, if you are using the
Xstandard Unix mail program, the simple line:
X  mailer=mail
Xwill suffice.
X    You will also note a couple of other comments in the shell script,
Xjust below the mailer definition, for other possible Unix conflicts.
X    With this, the (standard) Alex download feature should work
Xunaided as long as your system supports Kermit. Most Unix systems have
Xa version of Kermit running, so this should be no problem.
X    If you have difficulty installing Alex on a Unix system, please
Xsend electronic mail to msdos-request@ARDEC, and include a copy of the
X'man' page for your electronic mail program. We will be glad to do our
Xbest to help.
X
X    The format of an Alex library is deliberately simple.  First, all of
Xthe files to be sent are compressed (unless the ASCII option is used).  Then
Xthey are encoded using Btoa (again, unless ASCII).  Finally, they are
Xconcatenated together into one large file, separated only by a line that
Xbegins with several dashes and has the words "CUT HERE" in the middle.  If
Xthe ASCII option is used, then the "CUT HERE" line is followed by one more
Xline identifying the file name:
X
XASCII filename
X
X    Alex has three major advantages over other similar systems, like the
Xpublic domain Tarmail.  First, Alex can be ported to non-Unix systems (which
Xdo not usually have the 'tar' program required by Tarmail).  While it is
Xtrue that Alex is primarily a Unix shell script program, it turns out that
Xthe vast majority of the code in this script is for the user interface; very
Xlittle of it has anything to do with particulars of Unix.  Using the brief
Xdescription given above of the Alex library format, it should be easy to
Xwrite Alex in any shell (or batch) language on any operating system.  The
Xmajor parts of Alex are the public domain C programs (which is certainly not
Xtrue of Tar).  The only exception to the above is the ASCII option, which is
Xdecoded using some Unix-specific commands like Cut, Head, and Tail.
XHowever, this option is really not necessary.
X    The second advantage to Alex is that it is very easy to manually
Xbreak up an Alex library (unlike Tarmail).  Many electronic mail systems
X(like Msg and Mailx) have an 'undigest' command (@ in Msg) that breaks up a
Xsingle message into several messages, separating them at the location of
Xlines that begin with several dashes.  Therefore, an Alex-encoded library
Xcan be easily broken up by undigestifying the message and piping each
Xindividual message to Atob, and uncompressing any files that end in a .Z
Xextension.  My special version of Btoa and Atob are necessary, however, to
Xpreserve the file names.  (Use the '-f' option on Atob.)
X    The third advantage to Alex over Tarmail deals with modifying an
Xexisting Alex library.  Since files are separately encoded, and their names
Xclearly marked in the Btoa listing, a library of Alex files can be broken up
Xinto its constituent files, and files can be selectively replaced without
Xremaking the entire library.
X    Library sizes, incidentally, are about the same for Alex and
XTarmail.  (They both use Compress and Btoa.)
X    One last note: The old version of Alex (1.0) created libraries that
Xcan be used by the new version, but the converse is not true.  The old Alex
Xdid not compress files (nor did it uncompress them); the new one
Xautomatically compresses all files, but checks to see if the files are
Xcompressed before uncompressing them.  This makes Alex 1.1 and 1.2 upwardly
Xcompatible.  Versions before 1.1 also do not support the ASCII option, in
Xeither uploading or downloading.
X
X            --Ken Van Camp <[e-mail]>
X    U.S. Army Armament Research Development & Engineering Center
X                SMCAR-FSA-E  Building 329
X            Picatinny Arsenal, NJ  07806-5000
X              [phone]  (AV)880-3334
________This_Is_The_END________
if test `wc -l < alex.doc` -ne 571; then
    echo 'shar: alex.doc was damaged during transit (should have been 571 bytes)'
fi
fi        ; : end of overwriting check
echo 'x - undigest.c'
if test -f undigest.c; then echo 'shar: not overwriting undigest.c'; else
sed 's/^X//' << '________This_Is_The_END________' > undigest.c
X/* undigest.c: Undigest data from the input stream, and send output
X * to files named fileNN, where file is the parameter given on the
X * commmand line and NN is a numeric file number assigned by undigest.
X * The first file undigestified is named file0, the second file1, and
X * so on.
X * Written by Ken Van Camp, Picatinny Arsenal <[e-mail]>
X * Version 1.0, June 1986
X */
X
X#include <stdio.h>
X#include <sys/file.h>
X#include <strings.h>
X
X#define CR    '\012'        /* line feed */
X
Xchar    *dashes = {    "-----"
X};
X
Xmain (argc, argv)
Xint argc;
Xchar *argv[];
X{
X    char    *filname,        /* file name output mask */
X        line_buf[256],        /* line buffer */
X        filoutnm[40];    /* name of next file to create */
X    FILE    *filout,        /* output file */
X        *fopen();
X    int    filopen = 0,        /* flag output file open */
X        seqn = 0;        /* version # for output file */
X
X    if (argc < 2){
X        fprintf (stderr, "undigest: No filename specified\n");
X        exit (1);
X    }
X    filname = argv[1];
X
X    while (fgets (line_buf, sizeof line_buf, stdin)){
X        if (!filopen){
X
X            /* Time to open a new file. */
X
X            /* Make sure this isn't just a blank line */
X            if (*line_buf != NULL){
X                sprintf (filoutnm, "%s%d", filname, seqn);
X                if ((filout = fopen(filoutnm, "w+"))==NULL){
X                   fprintf(stderr,"undigest: Can't create %s\n",
X                    filoutnm);
X                   exit(1);
X                }
X                filopen = 1;
X                seqn++;
X            }
X        }
X
X        if (strncmp (dashes, line_buf, 5)){
X            /* No separator in this line */
X            fprintf (filout, "%s", line_buf);
X        }else{
X            /* Found separator; don't print this line */
X            /* Close the old file */
X            if (filopen)
X                fclose (filout);
X            filopen = 0;
X        }
X    } /* while */
X
X    if (filopen)
X        fclose (filout);
X}
________This_Is_The_END________
if test `wc -l < undigest.c` -ne 69; then
    echo 'shar: undigest.c was damaged during transit (should have been 69 bytes)'
fi
fi        ; : end of overwriting check
exit 0