From: <eric@cse.ucsc.edu> (Eric C. Rosen)
Newsgroups: comp.sys.mac.comm,news.answers
Subject: comp.sys.mac.comm Frequently Asked Questions [1/4]
Supersedes: <csmc-FAQ1_723889654@darkstar.ucsc.edu>
Followup-To: poster
Date: 10 Jan 1993 18:55:49 GMT
Organization: University of California, Santa Cruz (CE/CIS Boards)
Distribution: world
Expires: 14 Feb 1993 18:57:11 GMT
Reply-To: eric@cse.ucsc.edu
NNTP-Posting-Host: oak.ucsc.edu
Summary: This thread of four postings contains a list of Frequently Asked
	 Questions (with answers) for comp.sys.mac.comm. Anyone seeking
	 information about Macintosh telecommunications is encouraged to
	 read this FAQ before posting.
Keywords: FAQ
Originator: eric@oak

Archive-name: macintosh/comm-faq/part1
Last-modified: Sun Jan 10 1993

This is the Frequently Asked Question (FAQ) list for comp.sys.mac.comm

This list of frequently asked questions and answers is intended to help
reduce the number of "often asked questions" that make the rounds here
in comp.sys.mac.comm. Since comp.sys.mac.comm is intended as a forum to
discuss telecommunication (and related issues) that are specific to the
Macintosh, most questions about modems, telecommunications in general,
and other non-Macintosh specific communication questions are not listed
here. The proper newsgroup for such questions is usually comp.dcom.modems.

This list is posted periodically (about once a month) to the Usenet 
groups comp.sys.mac.comm and news.answers. The FAQ can be retrieved via
anonymous FTP from the following sites:

            Site                 Directory                File(s)   {Parts}
------------------------ ---------------------------- -------------------------
 rascal.ics.utexas.edu            mac/faq                communications.FAQ
 sumex-aim.stanford.edu        info-mac/report        comp-sys-mac-comm-faq.txt
 pit-manager.mit.edu     pub/usenet/comp.sys.mac.comm   c.s.m.c_FAQ_[1_4] {4}

It also available in the Macintosh SIG on Delphi for Delphi members.

This FAQ is purely a volunteer effort. Although every effort has been
made to insure that answers are as complete and accurate as possible,
no guarantee is implied or intended. The editor and contributors have
developed this FAQ as a service to Usenet. We hope you find it useful.

Please send your corrections, questions, and comments to the editor, 
Eric Rosen, at eric@cse.ucsc.edu.

             SHARE THIS INFORMATION FREELY AND IN GOOD FAITH.
             DO NOT DISTRIBUTE MODIFIED VERSIONS OF THIS FAQ.

================================================================================

                          **** TABLE OF CONTENTS: ****

[1] Modems and Cables

        [1.1] What kind of modem will work with my Macintosh?
        [1.2] What kind of cable do I need to use my external modem with my
                  Macintosh? (Includes cable pinouts)
        [1.3] What do V.32, V.42, bis, MNP, etc mean? 
        [1.4] How fast can the Macintosh serial ports really go?
        [1.5] How can I disable call-waiting when using my modem?

[2] File Formats and Conversion

        [2.1] What is a resource (or data) fork?
        [2.2] What is MacBinary?
        [2.3] What is BinHex? What is uuencode? What are atob/btoa ?
        [2.4] What is Apple-Single/Double ?
        [2.5] What do file suffixes like .hqx, .sit, .bin, etc ... mean
                and how can I convert such files back to normal Macintosh
                applications and documents?

[3] Macintosh File-transfers

        [3.1] What program(s) do(es) Kermit, FTP (client), and/or
                X,Y,Z-Modem and where can I get them?
        [3.2] What is the latest version of ZTerm?
        [3.3] What is the Communications Toolbox (CTB)?
        [3.4] Are there any public-domain or shareware Communication
                Toolbox tools that support Kermit, and/or X,Y,Z-Modem?
        [3.5] How can I transfer Macintosh files to/from my Macintosh and
                other non-Macintosh computers (eg: mainframes, Unix boxes,
                PCs)?
        [3.6] What's the best compression program to use when uploading
              files to an archive or BBS? Are there any other guidelines
              I should follow?
        [3.7] How can I use the programs that are posted to
                comp.binaries.mac?

[4] Introduction to AppleTalk (and Remote AppleTalk)

        [4.1] What kind of hardware do I need to set up an LocalTalk
                network?
        [4.2] How can I change the Chooser "user" and name of my
                Macintosh? Also: Why can I no longer change the name of
                my hard-disk?
        [4.3] What is AppleTalk Remote Access ?
        [4.4] Where can I get a Remote Access script for my modem? 

[5] Networking, MacTCP, Telnet, SLIP

        [5.1] What is MacTCP and what kind of hardware and software do I
                need to use it? 
        [5.2] What is the difference between AppleTalk, LocalTalk,
                EtherNet, EtherTalk, TCP/IP, etc?
        [5.3] What is Telnet, and is there a Telnet program for the
                Macintosh?
        [5.4] Is there a FTP (server) program for the Macintosh?
        [5.5] What are SLIP, CSLIP and PPP?

[6] MacX and Other Ways to Interface With Unix

        [6.1] Can I run X-Windows on my Mac?
        [6.2] How can I run MacX over a modem? Is it feasible?
        [6.3] What is MacLayers and what do I need to use it?
        [6.4] What is UW and what do I need to use it?
        [6.5] Is there a program that will convert between BinHex and
                MacBinary for Unix?
        [6.6] How can I create LaserWriter PostScript printer files and
                print them on an PostScript printer connected to a Unix
                network?

[7] Sending and receiving Mail and Usenet News with your Macintosh

        [7.1] How can I send/receive Internet mail with my Macintosh?
        [7.2] How can I read/post Usenet news with my Macintosh?

[8] Miscellaneous

        [8.1] I don't have FTP --- How can I access the various archives
                through e-mail?

Appendix

[A]     List of Common File Suffixes and Abbreviations

[B]     List of Macintosh archive sites available through the Internet

[C]     Vendor Information

[D]     Contributors

================================================================================
[1] Modems and Cables

[1.1] What kind of modem will work with my Macintosh?

        Any *external* Hayes compatible modem will work with your
        Macintosh. See comp.dcom.modems for more information about
        the many different external Hayes compatible modems. Such
        modems can be used with any computer (Macintosh, Unix box,
        MS-DOS PC, Amiga, etc) with a serial port (eg: Macintosh modem
        port) interface. However, there are modems that are designed
        specifically for use with the Macintosh. Internal Powerbook
        modems, ADB modems, and internal NuBus modems are all examples.

        Assuming you wish to use an external modem, your only other
        hardware consideration is to find an appropriate cable to connect
        it to your Macintosh. Especially at higher baud rates (9600 baud
        and up), a hardware-handshaking cable is recommended (see [1.2]
        for details). There are many non-hardware-handshaking cables
        being sold at reputable computer accessory stores, so it's
        recommended that you ask before buying.

        Various special modems exist with unique features; the most
        notable type is the dual FAX/modem. For more information,
        visit comp.dcom.modems or your local dealer: there are simply
        too many products to describe here.


[1.2] What kind of cable do I need to use my external modem with my
        Macintosh? 

        Most modems have a female DB-25 (25 pin) connector labelled
        RS-232C on their backsides. All Macintoshes since the Mac Plus
        use a mini DIN-8 (8 pin) connector for the two serial ports
        (modem and printer). Earlier models use the larger DB-9 (9 pin)
        connector. Finding a generic cable for any configuration should
        not be very difficult at most computer accessory stores. They
        are typically sold for around $25.

        However, especially at the higher baud rates (9600 baud and up),
        a hardware handshaking cable is highly recommended. Attempting
        to transfer files at high baud rates using a non-hardware-
        handshaking cable will likely result in repeated transmission
        errors, a drop in the transfer rate, and possibly an aborted
        transmission. Since many non-hardware-handshaking cables are
        still being sold, it's a good idea to ask before buying.

        If you want to "roll-your-own" or are having problems getting
        your modem and your Macintosh to communicate, read on. The
        serial ports on the Macintosh are not actually RS-232C ports
        but are instead RS-422 compliant, a similar but better standard.
        This explains some of the difficulty in implementing hardware-
        handshaking.

        One way to wire your cable is as below:

                Macintosh (DTE)                           Modem (DCE)
                    DIN-8                                    DB-25

                Pin  Signal                               Signal  Pin
                 1    HSKo   ---------------------------   RTS     4
                 2    HSKi   ---------------------------   CTS     5
                 3    TxD-   ---------------------------   TxD     2
                 4    GND    ---------------------------   GND     7
                 5    RxD-   ---------------------------   RxD     3
                 6    TxD+   (nc)                    .--   DSR     6
                 7    GPi    (nc)                    '--   DTR    20 
                 8    RxD+   ---------------------------   GND     7  

                    shield   ---------------------------   shield

                                Figure 1.2.1

        If your modem cannot be configured to ignore DTR, or if you
        are using an old 1200 baud or 2400 baud modem, the pinout in
        Figure 1.2.1 is probably best. However, if you are using a
        high-speed modem that can ignore DTR, and/or Remote AppleTalk,
        you should instead use the pinout in Figure 1.2.2, which is
        the pinout recommended by Apple:

                Macintosh (DTE)                           Modem (DCE)
                    DIN-8                                    DB-25

                Pin  Signal                               Signal  Pin
                 1    HSKo   ----------------------+----   RTS     4
                                                   '----   DTR    20

                 2    HSKi   ---------------------------   CTS     5
                 3    TxD-   ---------------------------   TxD     2

                 4    GND    ----+----------------------   GND     7
                 8    RxD+   ----'

                 5    RxD-   ---------------------------   RxD     3
                 6    TxD+   (nc)                    
                 7    GPi    ---------------------------   DCD     8

                    shield   ---------------------------   shield

                                Figure 1.2.2

        Note: You can find a pretty picture of this PICT by using 
        ResEdit to open the 'Apple Modem Extension' CTB. This PICT

        Note: Be careful! Although technically, you should not be able
        to damage either your modem or computer by using an incorrectly
        wired cable, you should always perform a connectivity test to
        double-check your wiring before using your homemade cable.
        Some serial devices place auxiliary voltages on non-standard
        pins.
        
        Note: If you are having trouble finding or soldering a mini DIN-8
        connector (they can be expensive and are rather small), Dave
        Alverson suggests purchasing a DIN-8 to DIN-8 cable (often sold
        as an Imagewriter printer cable), cutting it in half, and wiring
        each end to a DB-25 that can plug into your modem (resulting in
        *two* cables). However, before slicing, Jon Spear notes that
        it is a good idea to check for continuity between all the pins
        (otherwise you will not be able to wire each signal).

        Note: If you are running A/UX and are having difficulties
        controlling your modem from software, see the comp.unix.aux FAQ
        for the latest information on an A/UX specific cable.


[1.3]   What do V.32, V.42, bis, MNP, etc mean?

        Because these topics are universal telecommunications issues,
        they are more fully discussed in comp.dcom.modems. However, a
        short description of some of the more common abbreviations and
        buzzwords is given below.

        An excellent article on the subject of modems, including
        a guide to buying high-speed modems, is available from
        InfoMac (sumex-aim) and its mirror sites as the file
        info-mac/report/modem-guide-10.txt.
        
           Buzzword         What it typically means
        ---------------   ----------------------------------------------
        bit             : binary digit; amount of information necessary
                          to distinguish between two equally likely
                          events (such as the value of a binary digit)
        byte            : eight bits; size of a single ASCII character
        bps             : bits per second
        baud            : one analog signal state change; people usually
                          use baud and bps interchangeable although most
                          modern modems can encode multiple bits per baud
        Bell 103        : 300 bps U.S. Standard
        Bell 212A       : 1200 bps U.S. Standard
        LAP/M           : Link Access Protocol/Modem.
        MNP             : Microcom Networking Protocol (Proprietary)
        MNP5            : MNP extension; 2 to 1 data compression.
        V.32            : 9600bps, 4800bps
        V.32bis         : 14.4Kbps, 12Kbps, 9600bps, 7200bps, 4800bps
        V.42            : MNP 4 and LAP/M modem to modem error correction
        V.42bis         : LAP/M and 4-to-1 data compression.

                             Table 1.3.1


[1.4]   How fast can the Macintosh serial ports really go?

        The Macintosh operating system supports data rates up to 57600 baud,
        but the Macintosh serial hardware can support transfer rates that
        are much higher if they are externally clocked. Serial port
        sound-input-devices such as the Cedar Technologies SID and
        Farallon's MacRecorder, as well as AppleTalk boxes, use this trick
        to achieve transfer rates greater than 100 Kbps.
        
        Note: Powerbooks are known to have problems at extremely high
        data rates. These problems are caused by Power Manager overhead.
        A soon-to-be released Powerbook Tuner will hopefully cure this
        problem.

        
[1.5]   How can I disable call-waiting when using my modem?

        This varies depending on your local phone company, but often,
        if you preced the phone number you wish to tone dial
        with "*70," (omit the quotes but not the comma), you can
        disable call-waiting FOR THAT CALL ONLY.
        
        If you have a strictly rotary dial line, try preceding the
        phone number with "1170". 

================================================================================
[2] File Formats and Conversion

[2.1] What is a resource (or data) fork?

        A Macintosh file has two parts: a data fork and a resource fork.
        Text files and GIF image files are examples of Macintosh files
        that are usually stored completely in the data fork, and have
        an empty (or nonexistent) resource fork. Applications, as a
        a counter-example, store most if not all of their information
        in 'resources' in the resource fork and usually have an empty
        data fork.
        
        Because this two-forked organization of files isn't very common,
        transferring Macintosh files that have non-empty resource forks
        to non-Macintosh machines (such as Unix boxes, or MS-DOS machines)
        requires special encoding, described below.


[2.2] What is MacBinary?

        MacBinary is a standard way of taking a Macintosh file (both
        resource and data forks) and creating a new file with just
        a data fork. This new file can then be transferred through
        machines which know nothing about the native Macintosh file
        system, without losing the information stored in the resource
        fork.
        
        MacBinary also stores other information (such as the filename,
        creation and modification dates, file type and creator) about
        the original file.
        
        If you want to store some Macintosh files on a non-Macintosh
        computer, one way is to convert them to a MacBinary format file
        before transferring. Note that MacBinary files are useless to
        people who are not using Macintosh computers. MacBinary's
        purpose is to encapsulate *all* information contained in a
        Macintosh file for transport over a non-Macintosh medium. For
        this reason, you should not use MacBinary and/or BinHex to
        post GIF images, for example, to Usenet because (1) GIF images
        contain no Macintosh specific information and (2) doing so will
        make it impossible for most non-Macintosh users to display your
        image.

        Although a Macintosh program (called MacBinary) does exist
        to do the converting to and from MacBinary, almost all modern
        Macintosh telecommunications programs have the capability of
        converting and unconverting MacBinary files for you. ZTerm,
        for example, can be configured to automatically detect when
        a MacBinary file is being received and to convert this file
        to its original representation; or, if you are uploading,
        ZTerm can optionally encode the file into MacBinary before
        sending. Fetch, White Knight, and most other commercial and
        shareware products have equivalent or similar capabilities.
        
        Dennis Brothers designed the original MacBinary standard many
        years ago. Yves Lempereur incorporated this standard into
        his Binhex 4.0 program (see [2.3]), solving a major problem
        on Compuserve. About a year later, around the time the Mac Plus
        came out, group discussions on Compuserve led to an enhancement
        of the original MacBinary standard. Since then, BinHex 4.0 and
        the new MacBinary have become the standard way of encapsulating
        Macintosh files for transferring over foreign systems throughout
        the Internet, Usenet, and elsewhere.

        MacBinary I is the name given to the old MacBinary standard.
        MacBinary II is the name given to the new MacBinary standard
        which everybody uses today; in common usage, MacBinary means
        MacBinary II.
        
        
[2.3] (a) What is BinHex? (b) What is uuencode? (c) What are atob/btoa ?

        (a) A "binary" file is usually intended to describe a file which
        does not always have the high bit in each byte set to zero.
        Text and BinHex files are the most common examples of non-binary
        data. Programs and images are common examples of binary data.
        MacBinary files are specially encoded binary files (see 2.2]).
        
        Unfortunately, many network e-mail and Usenet gateways are only
        receptive to non-binary files. To make it possible to send
        binary files such as Macintosh MacBinary files through e-mail
        or Usenet, it is necessary to convert these files to a text-
        compatible form. BinHex and uuencode are two different ways
        of doing this. Both BinHex and uuencode result in files that
        are larger than the original binary version.
                
        BinHex 4.0, by Yves Lempereur, is a binary to text translator
        that can directly encode any Macintosh document (ie: it knows
        how to convert information in both the resource and data forks).
        BinHex files can be easily recognized since they begin with the
        line:
        
                (This file must be converted with BinHex 4.0)
        
        and are followed by a line starting with a colon, ':'. The
        BinHex encoding of the file follows, and is ended with another
        colon.
        
        There is in fact a program called "BinHex 4.0" in various
        archives, but you don't have to use it to convert files to and
        from BinHex. Many programs, including the popular compression
        programs "Compact Pro" and "StuffIt" allow you to convert BinHex
        files on your Macintosh. There are even various Unix utilities
        (see [6.5]) that manipulate BinHex, MacBinary, and other types
        of Macintosh files. Just about every Macintosh program posted
        to Usenet appears in BinHex 4.0 format. Most FTP sites also
        store their Macintosh archives in BinHex format to allow users
        who don't have (or forget to use) binary mode in FTP to 
        successfully transfer files. BinHex files are usually denoted
        by the suffix ".hqx". The specifications to BinHex, should you
        be interested, are available at InfoMac archives (retrieve
        the file tech/binhex-40-specs.txt).
        
        Useful utility programs for converting to and from BinHex 4.0
        include:
        
            o Binhex 4.0 -- the original BinHex 4.0 application; free.
            o Stuffit Expander 3.0 -- a much more powerful utility
              which can encode and decode BinHex, Stuffit, Compact Pro,
              and Applelink archives. Also free.

        Note: On Unix (and other non-Macintosh machines), you can use
        the programs described in [6.5] to manipulate BinHex files.

        There is also a program/format called "BinHex 5.0"; it is NOT
        a more advanced version of "BinHex 4.0" but rather a separate
        _binary_ format (it uses the entire eight-bit ASCII character
        set and is thus not suitable for Usenet postings or e-mail)
        that was the precursor to MacBinary (see [2.2]). Converting
        a file with BinHex 5.0 and then using BinHex 4.0 is another way
        of converting a native Macintosh files with data and resource
        forks into a format that can be e-mailed or posted (and then
        reconstructed). MacBinary, however, is almost always used in
        preference to BinHex 5.0.

        (b) "uuencode" is a binary to text translator that serves the
        same purpose as BinHex, except that it knows nothing about the
        Macintosh resource/data fork structure. uuencode was designed to
        allow Unix binary files to be easily transferred through text-
        only interfaces, such as e-mail. Every uuencoded file contains
        a line similar to:
        
                begin 644 usa-map.gif
                
        followed by a series of lines of 60 ASCII text characters that
        begin with the letter 'M'. The file ends with a line containing
        the word 'end'. There may be other special keywords included.
        Usually, you won't find Macintosh files in uuencode format;
        however, most non-Macintosh specific binary data posted to Usenet
        is uuencoded, so if you wish to use any of this data (such as
        images posted in alt.binaries.* and elsewhere), you will need
        to deal with uuencode. The programs 'uuencode' and 'uudecode'
        exist on most Unix systems. If not, ask a local expert to find
        them. Several programs allow you to convert to and from uuencode
        using your Macintosh; among these are UULite 1.4 and Tiger 1.11.
        uuencoded files are usually denoted by the suffix ".uu".

        There is a StuffIt translator to handle uuencode conversion.
        
        (c) atob and btoa are programs typically found on Unix systems
        that also convert between binary and ASCII-printable character
        sets. Although not as popular as uuencode, btoa produces smaller
        text-compatible versions of binary files that can be e-mailed or
        posted on Usenet. Check your local man pages for details.
        
        There are StuffIt translators to handle atob/btoa conversion.
        
[2.4] What is Apple-Single/Double ?
        
        AppleDouble is another means of storing Macintosh files on
        non-Macintosh computers or filesystems, particularly on Unix
        filesystems that also allow files to be mounted under the
        Macintosh operating system via AppleShare (or an equivalent
        product).

        AppleDouble files are actually two files. The data fork
        of the corresponding Macintosh file is stored in a single
        file just as it exists on the Macintosh using the original
        filename. The resource fork is stored in a second file whose
        name is obtained by prefixing the original filename with '%'.
        More extensive documentation is available at ftp.apple.com.
        
        A few Macintosh programs decode these files; one such utility
        is Tiger 1.11. The macutils Unix utilities [see 6.5] may also
        be useful.
        
        If you are trying to figure out how to access the files in
        the 'mac.bin' directory at ftp-archive maintained by the
        University of Michigan, don't bother; all those files exist
        in .hqx format in the 'mac' directory.

        
[2.5] What do file suffixes like .hqx, .sit, .bin, etc ... mean and how
        can I convert such files back to normal Macintosh applications
        and documents?
        
        Most files available by FTP or posted to Usenet are modified
        twice to allow them to more easily pass through foreign computer
        systems. Files may be compressed to make them smaller, and/or
        they are almost always translated to either BinHex (.hqx) or
        MacBinary (.bin) format (see [2.2] and [2.3] for an explanation
        of these formats).
        
        How a Macintosh file has been translated and compressed for
        transmission is indicated by its suffix.  Normally a file will
        have a name similar in form to: filename.xxx.yyy, where:
        
                .xxx indicates how it was compressed
                .yyy indicates how it was translated
        
        Usually, .xxx is one of: .cpt, .dd, .sea, .sit
        Usually, .yyy is one of: .bin, .hqx, .image
        
        To convert a file back to its native Macintosh format, you will
        typically need to go through one step per suffix. For example,
        the filename "Swatch.cpt.hqx" indicates that a Compact Pro
        archive (.cpt) "Swatch" has been translated to BinHex (.hqx).
        To recreate the file(s) in the original archive, you must
        first 'undo' the BinHex transformation, creating a Compact Pro
        archive, and then open the Compact Pro archive and extract
        the file(s) in the archive.

        You can use the following table to determine what Macintosh
        programs decode which formats. For a more complete description
        of the various Macintosh archival programs, see the excellent
        FAQ for comp.sys.mac.apps.

      Suffix: .sit  .cpt  .hqx  .bin  .pit  .Z  .image  .dd  .zip  .uu  .tar
  Extractors
----------------------------------------------------------------------------
 StuffIt 3.0  | X     X     X     X     X    X           X     !    !     !
 $ Expander   | X     X     X
 Compact Pro  |       X     X
 UULite 1.4   |                                                     X
 MacCompress  |                              X
 SunTar       |             X     X     X                                 X
 BinHex 5.0   |                   X
 BinHex 4.0   |             X
 DiskDoubler  |                                          X
 UnZip        |                                                X
 DiskCopy     |                                    X
 Packit       |                         X

                                Table 2.5.1

      ! Note: StuffIt Deluxe 3.0.3 includes translators for .tar, .uu,
        MacBinary, atob, btoa, AppleLink packages, AppleSingle, DiskDoubler,
        and Unix compress. These translators can also be used with StuffIt
        Lite. .arc and .zip translators are also distributed with StuffIt
        Deluxe, but remain part of the commercial package.
      
      $ 'Expander' refers to Stuffit Expander 3.0 which can decode BinHex,
        Stuffit, Compact Pro, and Applelink archives. It supports drag-
        and-drop under System 7. Stuffit Expander is distributed free by
        Aladdin Systems Inc. 


        The following file suffixes indicate formats that are native
        to the Macintosh and which can be manipulated using the indicated
        programs:
        
        .bin    MacBinary files; see [2.2]
        .cpt    Compact Pro archive files; [see 3.6]
        .dd     DiskDoubler archive files; [see 3.6]
        .hqx    BinHex files; see [2.3], [3.7]
        .image  Apple DiskCopy disk image file (typically used for
                distributing system software); latest version available
                via anonymous ftp from ftp.apple.com
        .pit    Packit files; [see 3.6]
        .sea    Self-extracting archive files; this usually denote an
                application which can be double-clicked upon to create
                a decompressed version of the archive
        .sit    StuffIt archive files; [see 3.6]
        .sitd   mistakenly used to indicate files created by StuffIt
                Deluxe; *all* StuffIt files should be given the .sit
                extension (says the author!)
        
                                Table 2.5.2

        
        The following file suffixes indicate formats that are not native
        to the Macintosh, but in most cases, files of these types can
        be manipulated on the Macintosh using the indicated programs.
        
        .arc    MS-DOS PC archive file; ArcPop, MacArc
        .arj    MS-DOS PC archive file; unArjMac
        .gif    Compuserve Graphics Interchange File; many programs,
                free, shareware and commercial exist to display and/or
                modify these images; some of the popular shareware ones
                are: QuickGIF and GIFConverter.
        .lzh    MS-DOS PC archive file; LHarc or MacLHa
        .shar   Unix shell archive file; Unshar 1.5
        .uu     Unix uuencoded files; see [2.3]
        .Z      Unix 'compress' archive file; MacCompress 3.2
        .zip    MS-DOS PC archive file; UnZip, ZipPop

                                Table 2.5.3
Newsgroups: comp.sys.mac.comm