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Newsgroups: comp.sys.mac.comm,news.answers,comp.answers Path: bloom-beacon.mit.edu!news.kei.com!MathWorks.Com!europa.eng.gtefsd.com!darwin.sura.net!udel!princeton!tucson.Princeton.EDU!davido From: davido@phoenix.Princeton.EDU (David L. Oppenheimer) Subject: comp.sys.mac.comm Frequently Asked Questions [1/4] Message-ID: <csmc-FAQ1_765398487@Princeton.EDU> Followup-To: poster Summary: This is the comp.sys.mac.comm Frequently Asked Questions list; its intent is to provide information specific to Macintosh computer communications, including modems, networks, and the like. You are encouraged to read this FAQ before posting to the newsgroup. Originator: news@nimaster Keywords: FAQ Sender: davido@phoenix.Princeton.EDU Supersedes: <csmc-FAQ1_762705652@Princeton.EDU> Nntp-Posting-Host: tucson.princeton.edu Reply-To: csmc-faq@phoenix.Princeton.EDU Organization: Princeton University Date: Sun, 3 Apr 1994 18:42:06 GMT Approved: news-answers-request@MIT.Edu Expires: Sun, 8 May 1994 18:41:27 GMT Lines: 679 Xref: bloom-beacon.mit.edu comp.sys.mac.comm:33766 news.answers:17566 comp.answers:4693 Archive-name: macintosh/comm-faq/part1 Last-modified: Wed Mar 09 1994 This is the Frequently Asked Questions (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, news.answers, and comp.answers. Latest versions of the FAQ can be retrieved via anonymous FTP from the following sites: mac.archive.umich.edu: mac/misc/documentation/compsysmaccommfaq.txt sumex-aim.stanford.edu: info-mac/comm/info/comp-sys-mac-comm-faq.txt rtfm.mit.edu: pub/usenet/comp.sys.mac.comm/c.s.m.c_FAQ_[1_4] c.s.m.c_FAQ_[2_4] c.s.m.c_FAQ_[3_4] c.s.m.c_FAQ_[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. It has been formatted in setext format for your browsing convenience; use a setext browser, such as EasyView, to take advantage of setext. Please send your corrections and comments to the editor, David Oppenheimer, at csmc-faq@phoenix.Princeton.EDU. SHARE THIS INFORMATION FREELY AND IN GOOD FAITH. DO NOT DISTRIBUTE MODIFIED VERSIONS OF THIS FAQ. DO NOT REMOVE THIS NOTICE OR THE TEXT ABOVE. (INCLUDING THE 'LastModified' HEADER; THANKS.) ================================================================================ **** 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 Apple Remote Access ? [4.4] Where can I get a Remote Access script for my modem? [5] Networking, MacTCP, Telnet, SL/IP, PPP [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 (client/server) program for the Macintosh? [5.5] What are SL/IP, CSL/IP and PPP? [5.6] How does MacTCP resolve names into IP addresses? [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 are UW and MultiSession? Are there other programs like MacLayers? [6.5] Is there a UNIX program that will convert between BinHex and MacBinary? [6.6] How can I create LaserWriter PostScript printer files and print them on a PostScript printer connected to a UNIX network? [6.7] What is the Columbia AppleTalk Package (CAP)? [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? Appendices: [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. There are too many to list or review here. The USENET newsgroup comp.dcom.modems is a good place to ask questions 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 (e.g.: 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 Tool Extension CTB tool. 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), it is suggested you purchase a straight-through DIN-8 to DIN-8 cable (often sold for use with serial port switches), cut it in half, and wire each end to a DB-25 connector that can plug into your modem (resulting in *two* cables). Note: The GPi pin is unused on all but the AV Macs. The pinout diagrams are correct. 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. Many people routinely ask for a pinout diagram for the mini DIN-8 connector; Figure 1.2.3 shows the pinout as if you were looking at the (female) connector on your Macintosh; the (male) cable connector will be a mirror image. (Figure artwork by Ben Cranston) Mini DIN-8 Macintosh Serial Connector Pinout /------###------\ 1 HSKo Output Handshake / ### \ (Zilog 8530 DTR pin) / \ 2 HSKi/CLK Input Handshake *OR* / [|] [|] [|] \ External Clock / 8 7 6 \ 3 TxD- Transmit data (-) | | | | 4 Ground Signal ground | === === === | | 5 4 3 | 5 RxD- Receive data (-) | | | | 6 TxD+ Transmit data (+) \----+ === === +----/ \###| 2 1 |###/ 7 N/C (no connection) \##| |##/ \| |/ 8 RxD+ Receive data (+) \------###------/ ### Figure 1.2.3 Finally, it should be noted that there is no *best* RS-422 to RS-232 cable. You'll see many different wiring diagrams posted to Usenet. Each usually has its own purpose and champion; the two given in this FAQ, however, are fairly generic and one or the other should work with most modems being sold today. [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/comm/info/modem-guide-11.hqx. 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.32terbo : psuedo-standard extending V.32bis to 16.8, 19.2 kbs 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. System 7.1 is supposed to solve or alleviate these problems. Note: AppleTalk being active can degrade serial port performance, as can ethernet-network traffic. Turning of AppleTalk via the Chooser, or disconnecting the ethernet transceiver, are work-arounds. [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". In the United Kingdon, the code to use #43#. ================================================================================ [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. In fact, due to some bugs, it's best to use some of the other more powerful utilities, such as HQXer, DeHqx, StuffIt Expander and other StuffIt programs, and Compact Pro, to name only a few. UNIX utilities (see [6.5]) that manipulate BinHex, MacBinary, and other types of Macintosh files are also available. StuffIt Expander has the advantage of also being able to automatically expand StuffIt, Compact Pro, and Applelink archives. Just about every Macintosh program posted appears as a BinHex archive. Some Macintosh archives also store their files in BinHex to allow users who don't have (or forget to use) binary mode in FTP to succesfully transfer files. BinHex files are denoted by the suffix ".hqx". The specifications to BinHex, should you be an interested programmer, are available at the University of Michigan's Macintosh archive site as mac/misc/documentation/binhex4.0specs.txt, or at InfoMac sites as dev/info/binhex-40-specs.txt . 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 news 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 ASCII text characters (which are normally 60 characters long and begin with the letter 'M'). The file ends with a line containing the word 'end'. There may be other special keywords included. Usually, one 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 the 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 UUTool 2.3.2 and UULite 1.4.2. uencoded 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. Eudora 1.4 and later also handles this format. 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 ! ! ! $ Expander | X X X Compact Pro | * X X UULite 1.4.2 | X MacCompress | X SunTar | X X X X BinHex 5.0 | X BinHex 4.0 | X DiskDoubler | * X X ZipIt | X UnZip | X DiskCopy | X Packit | X Table 2.5.1 ! Note: StuffIt Deluxe now 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. In order to expand DiskDoubler archives, StuffIt uses inter-application communication and hence requires DiskDoubler to be installed. $ 'Expander' refers to StuffIt Expander 3.0.7 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. * StuffIt formats after 3.0 are recognized 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 denotes 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 Amiga or old 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 .z GNU ZIP file; typically created on UNIX .zip MS-DOS PC archive file; UnZip, ZipPop Table 2.5.3