University of Chicago Campus Computer Stores
Technical Support Note:
Contents:
You may have already heard about online services such as America Online, CompuServe, or Prodigy, or about the Internet and the World-Wide Web. These services are accessed using personal computers that send and receive data over ordinary phone lines by the use of a device known as a modem. Perhaps you are interested in checking your email account from home, or transferring files between your home computer and your office computer without having to carry disks back and forth, or maybe you want to print the latest draft of a proposal you just finished revising at home to a networked printer at another location. Modems, when combined with the appropriate communications software, will allow you to do all of these tasks.
A modem converts digital signals from your computer into audible tones which can be transmitted over ordinary analog phone lines. This process is called modulation. On the receiving end, a modem demodulates the analog signals arriving over the phone line into electrical signals which are then fed to the computer. MOdulation and DEModulation accurately describe what modems do.
You can use a modem and a personal computer to send text files, software programs, graphic images, sound files, reports, or commands to a remote system. Your particular brand of computer makes no difference; whether you have a Dell, Macintosh, Compaq, or a laptop, you can send files to other computers. In fact, with the right cable and a little tweaking, you can use the exact same external modem with an IBM, or a Macintosh, or a Unix workstation. Internal modems are specific to certain models and are not as easy to swap as external modems.
The first decision you need to make before you buy a modem is whether to get an external or an internal model. An external modem comes in a separate box which is usually constructed from plastic or aluminum. Typically, external modems feature an array of lights set in a display panel that offers important information when you are trying to troubleshoot your setup. External modems almost always come with a separate power adapter (although Global Village at one time produced a line of modems that draw power from any available ADB port on Macintosh machines). You also need a correctly wired cable to connect your modem to an available serial port on your computer. If you decide to purchase a high-speed modem, especially if you plan to use your modem on a Macintosh system, you must be certain that your cable correctly supports hardware flow control (RTS/CTS). We will talk about flow control in greater depth in the Troubleshooting section at the end of this document.
Internal modems are printed circuit boards that take up one of the available expansion slots inside of your computer. Internal modems are designed to work with certain types of computers (IBM, Macintosh, etc.) and will only work with that type. For the most part, internal modems are only available for DOS/Windows machines; very few Macs (other than PowerBooks) support internal modems. Internal modems usually include an onboard speaker that can be of great help when you are trying to diagnose a communications problem. Internal modems provide their own serial port and do not require a separate power adapter or a modem cable.
The Campus Computer Store does not generally recommend internal modems (except for laptops and PowerBooks). An external modem is portable and may be used on a different computing platform. If you upgrade an existing modem, you will find it much easier to sell your external modem. If your external modem fails, you still have the use of your computer while you are getting your modem repaired. External modems are easier to troubleshoot and they do not require that you open your computer's casing every time you need to change a DIP-switch setting. Finally, on Intel machines especially, internal modems are often difficult to configure, especially if you have several other expansion cards installed in your machine. (Windows 95's autoconfigure utilities may offset some of this, if it recognizes all your cards.) If you feel confident about your installation skills, you can purchase internal PC modems from Elek-Tek, CompUSA, or any mail-order vendor.
PCMCIA (or "PC Card") modems form a sort of gray area between internal and external modems; their design is more like an internal modem, but in theory, any computer with a PCMCIA slot of a given type should be able to use a PCMCIA modem of that type. In practice, there's still sufficient variance among different machines to cause occasional compatibility problems, and there are often driver problems as well between Macintosh and PC machines. It is now possible to purchase a PCMCIA modem card which will work on any PC or Macintosh with a Type I/Type II PCMCIA slot (though it's necessary to buy extra hardware for a desktop machine); however, there are only a few modems for which this is true (the MegaHertz CruiseCard is good for this, in our experience) . At present time, though, PCMCIA modems are really only an option for PC laptops or notebooks and some PowerBooks, and even then you should be careful to purchase a reputable brand name modem and make sure that support will be available for it, in case you run into problems.
Your next important decision depends upon evaluating your needs and matching those needs against the variety of features available in different modem models. Here is a quick checklist of features you should be aware of before buying a modem:
You should think seriously about which features you need. Many of these features are now standard, and you'll have a hard time finding a modem without them (for example, almost all modems are now fax-capable). Others are harder to find, and may be very expensive. Sometimes you'll have a trade-off between convenience, expense, and supportability, and knowing which features you really need may simplify your decision process.
Another decision affecting speed involves compatibility and price. Many users seem to think that a modem will be more or less compatible with dial-ins solely because it is slower or faster -- i.e., that a 28.8kbps modem will be more compatible with other modems simply because it is a 28.8 modem, or a 14.4kbps modem will be less compatible. This is an incorrect perception. The actual issue is what software you're going to be using. For SLIP or PPP, you want the fastest modem possible. For Lexis/Nexis, a slower modem, while perhaps not ideal, will probably be sufficient. It's true that some services may have slow dial-ups (although more and more are moving to fast modems); however, your modem manual should have instructions for stepping down a fast modem to a slower speed, if that's necessary.
If you think that you may want to transfer programs or large data files (a couple hundred kilobytes in size or larger), or use AppleTalk Remote Access, Timbuktu, Close-up, or any similar program, or if you are interested in a dial-up SLIP or PPP Internet connection, get at least a 14.4K V.32bis modem. Faster speeds will also work fine, but don't buy a used 2400 bps modem for these purposes. If you will frequently need to access online databases, such as Lexis/Nexis or WestLaw, we would suggest that you purchase a 14.4K modem, even though you will probably have to enter special configuration information into your communication program's setup file. (You can call Lexis/Nexis for help on how to change the default modem init string included in their software's setup.)
In addition to V.34bis, Rockwell and US Robotics have recently released independent protocols (K56flex and X2, respectively) for attaining up to 57,600 bps on standard phone lines (though FCC EMF restrictions have forced them to limit themselves to 56,000 bps - hence the term "56K modems"). Essentially, these protocols take advantage of the phone companies' digital routers to compress and encode data, allowing a provider who has made appropriate arrangements with his local telephone company to push data out at an incredibly high rate of speed. Things to note about 56K modems:
Modems have added the ability to send and receive facsimiles over the past couple of years. This additional feature is very inexpensive. You need to keep in mind that a fax modem is no substitute for a real fax machine. If you are a heavy user of fax technology, don't expect a fax/modem to handle your faxing needs. If, on the other hand, you occasionally need to fire off a fax, a fax/modem is a wonderful device. For sending important letters late at night from your home, a fax/modem can't be beat. If you occasionally would like to receive faxes, you should consider buying a fax/modem as well.
Laptop and PowerBook owners fall under a another category of users who should buy a fax modem. If you are on the road, it is easy to use any hotel fax machine as your virtual printer. Create your document on your PowerBook, and then fax it down to the lobby. You have just saved yourself the hassle of carrying the extra pounds that a portable printer would add to your luggage. A fax modem can also compensate for not being attached to a network. You can still fax in your documents while away from your office and thereby enable your co-workers to have access to your work. One of the nice features of a fax modem is that the image quality of your documents will be superior to the quality of documents sent using a regular fax machine.
You may have difficulty sending faxes to older fax machines; don't be surprised if you find one or two older machines that are incompatible with your fax modem. Also remember that the fax software included with many modems is, as they say, from the low bidder; you may have fewer problems if you buy a good third-party fax package (such as WinFax Pro for a Windows or Windows 95 machine). A final warning concerning fax software: sometimes fax software, especially when set to auto-answer incoming calls, will interfere with data communications programs such as Eudora (over direct dial-up), MicroPhone, ZTerm, and SLIP or PPP software. Disable your fax software before initiating a communications session.
Customers are often intrigued by ads for internal PC modem boards that offer features that combine fax capability with data transmission as well as an answering machine and electronic mailbox. We are wary of this type of unit, since we have, as yet, seen very few reliable implementations of this idea, and the configuration of such machines is often a little hairy; additionally, they tend to be on the expensive side. The situation is improving, though; Cypress Research's MegaPhone application, for example, seems to be fairly decent.
Related to answering machine software is DSVD, "Digital Simultaneous Voice/Data". This is a new protocol being developed independently by several different modem vendors, which allows you to actually carry on a voice conversation over your modem while simultaneously maintaining a high-speed data connection. This is very new technology, however, and each vendor has their own way of doing it; as a result, it's very expensive, and doesn't work unless the modem you're connecting to is a DSVD modem from the same manufacturer. CCS emphatically does not recommend this technology at this time. (Motorola and Rockwell both recently submitted proposals for a DSVD standard to the International Telecommunications Union in 1996, but nothing has been heard on this, and as of this writing DSVD modems are very hard to find; it's quite possible that the expense of DSVD has effectively killed the technology.)
Some modems offer a CallerID panel. If you plan on running a BBS, or are setting up a high-security remote LAN access modem bank, Caller ID might prove to be a useful feature; however, in other situations, it's not clear that a modem with CallerID offers anything over a more standard CallerID display.
The best way to upgrade your modem is often to sell it and buy a new one. When a new standard comes out offering higher speeds and additional features, you have to compare the cost of upgrading the modem to selling your current modem and purchasing a new model. Sometimes it makes more sense to pay the manufacturer for a daughterboard upgrade, sometimes you will come out ahead by unloading your old modem.
Upgrades come in a couple of different flavors. The old-fashioned way involves a ROM or hardware upgrade. In this case, you open your modem's case, pop the old ROM out, and install a new ROM chip. US Robotics and Hayes at one time used this approach (called "socketed ROMs") on their high-end modem lines. Along similar lines, with some low end modems, when a new protocol is released you can send the modem back to the factory for an upgrade, or the manufacturer might send you a daughtercard to install in the modem yourself.
The more modern approach is a software upgrade, typically referred to as a "Flash ROM" upgrade. High-end modems have supported this feature for a few years; now it's starting to appear in mid-range and even low-end models. The big advantage of Flash ROMs is that when a new standard is released (such as whatever the final version of the 56K standard turns out to be), you will be able to download the new software from the Web and upgrade your modem without even disconnecting it from your computer. (Subject to whatever fees your modem's manufacturer wants to charge you to unlock the upgrade, of course!)
In general, you should try to get a Flash ROM upgradeable modem if at all possible. At the very least, watch out and make sure it's hardware upgradeable; some very low-end modems have no upgrade path whatsoever, and if something is wrong with it, your only recourse is trying to talk the manufacturer into exchanging it for one with newer ROMs. Having a clear upgrade path of some sort will eliminate that particular difficulty.
Integrated Service Digital Network, or ISDN, is a standard for digital telecommunications. Established in the mid-80s, it's only now gaining momentum, as the need for fast network services is beginning to hit the home front; if you have a need for a REALLY fast data connection, ISDN might be the way to go. Since ISDN uses an entirely different technology from the existing telephone system, it can achieve two or three times the speed you can get with a "normal" V.34 modem, and a much cleaner, more reliable connection. Caveats:
There are a large number of rivals to ISDN for providing high-speed networking at a low cost. Most of these rely on "Digital Subscriber Lines", or DSL; and there are a lot of them, each one sticking its own letter in front of "DSL" - hence the collective term for all of them is "xDSL". Only one of the xDSL solutions (HDSL) is in any kind of widespread use at this point, but in general, they all provide data-only service (NO telephone service) over a leased line at speeds higher than ISDN, but lower than T1 or T3 (the connections all the major Internet service providers use). The various xDSL systems are all aimed more at corporate or business users, and will probably be priced out of the range of private individuals. Dan Kegel's ISDN page also has some information on xDSL, with a special focus on ADSL, the likely replacement for HDSL.
The major competitor for "something better showing up",though, is cable modems. In theory, the cabling used by cable TV companies is a high-grade networking cable, capable of transmitting data at speeds that put ISDN to shame; they only need to develop some kind of box you can plug in at home that will transform data from your computer into something that can be sent back over the cable -- the "cable modem" in question. In practice, there are still a LOT of bugs to work out, the big one being that all their networking setup assumes data will go only one way, from the cable company to your TV. Nonetheless, a number of companies are looking into the possibility of providing this service, though only one (MediaOne Express, at http://www.mediaone.com/express/) seems to be rolling it out. Two things to note: First, it seems very likely that the eventual cable modem solution will provide a high-speed download (i.e., other sites to your computer), but upload times (your computer to somewhere else) comparable to a standard 33.6 modem; this would make cable modems less practical than ISDN for such things as hosting a web page (and ISDN is bad enough for that purpose). Second, at present time MediaOne is only providing cable modem service to a few Chicago suburbs, with plans to extend to other suburbs; no one has announced any intention to provide service in Chicago city limits. As a result, delaying buying a modem until cable modem services are available may be rather frustrating.
David Gingold maintains an exhaustive list of cable modem information sources on the web at http://rpcp.mit.edu/~gingold/cable/. Check out especially the sections on cable periodicals and papers (the latter of which includes Gingold's own Master's thesis on this subject).
Unfortunately, modems must be configured for each individual service you dial into. If you are able to use your modem out of the box to connect to a wide variety of data services and networks, congratulations! You are very lucky indeed.
In general, you should resist the temptation to jump immediately into your communications program after purchasing a modem. Instead, at least skim through the manual that comes with your modem. Have at least some idea of what AT commands are and how to issue them to your modem. Try using your communications program to examine the current active settings in your modem.
It is not necessary to memorize all the commands and settings listed in your modem manual. If you grasp a few important concepts, you can solve 95% of the problems that you are likely to encounter. Here are the areas to focus on when trying to troubleshoot:
Many users ask us about the following hypothetical situation: if they purchase a 14,400bps modem, how fast will it transfer data to a 2400 bps modem? The answer is always the same: the transfer cannot be any faster than the highest speed that both modems have in common, in this case that would be 2400 bps.
Q: I have installed the U. of Chicago's Eudora software for dial-up use with my high-speed modem but I never connect properly to the server (753-0975). What are the "magic" modem strings that I need to enter into Eudora's "custom" modem field under the "Communications" settings?
A: The following init strings have been tested and will work just fine for dialing into Quads/Kimbark/Ellis with Eudora:
*: Strings for these modems may still need tweaking.
Note: 0 = "zero" not the letter "O". Also, these initialization strings apply ONLY for direct dial-up with Eudora; if you are connecting over SLIP (using the ACS Connectivity Package for Mac v3.0, for example), these initialization strings should not be necessary.
Q: I'm using the string you give for Eudora above on the PowerPort Mercury on my PowerBook 500, and my outgoing messages are all screwed up -- lots of missing characters or lines, and sometimes the messages just bounce for no reason. What's wrong?
A: You need version 2.5 of the GlobalFax software. Contact Global Village at 408-523-1050 or by email at techsupport@globalvillag.com to find out how to to upgrade.
Q: I'm trying to use Eudora 1.5.x with a PC Card modem, but Eudora keeps claiming that it can't find my modem or that it's in use. What's wrong?
A: You probably need to tell Eudora you're using a PC Card. Go under the Special menu to Communications; your Method should be "Calypso", and "Connection Tool" should be "Serial Tool". Hold down the Option key and click where it says "Serial Tool". Choose the "PC Card" icon for your Current Port in the window that pops up when you do this.
The other possibility is that you have configured Eudora to connect with direct dial-up, but are also running SLIP. If you have SLIP installed, try going under the "Special" menu to "Settings", and switch your "Connection Method" from "Communications Toolbox" to "MacTCP".
Q: I've used Eudora 1.3.1 for a long time and it's worked fine, but recently it's started freezing whenever I try to send or receive mail, or make complaints that it can't find the mailserver. What happened?
A: The incoming modem pool, and the software for many of the mailservers on campus, were extensively upgraded during the Autumn '95 quarter. Unfortunately, it's turned out that, although the upgrades represent a definite improvement for most purposes, they cause problems for older versions of Eudora on an apparently random selection of modems (probably dependent on the quality of phone lines you're connecting from). The solution is to upgrade to Eudora 1.5.1 or later. The newer version of Eudora and documentation for configuring it are in the ACS Connectivity Package version 2.0 or later, available at the Campus Computer Stores. (A newer version is also available on the ACS Roomservice AppleShare server; however, ACS will not support installations downloaded from this source.)
Q: I'm trying to use Eudora on my Global Village TelePort Gold II/TelePort Gold II for Performa. It keeps giving me the error "Eudora said DATA, SMTP server said:", and then things get strange....
A: You need to upgrade your version of the GlobalFax software to 2.5.5 or later. Check your Control Panels; if you have a TelePort Serial control panel, you'll need to upgrade to version 2.5 first -- contact Global Village at 408-523-1050 or by email at techsupport@globalvillag.com. If you have a TelePort control panel, you just need the 2.5.5 update; you can get that from the CCS bbs over AppleShare (in the "Computer Stores" zone) or over your modem (dial 312-702-2146, 8N1, with TeleFinder or a terminal emulator), or you can download it directly from Global Village's FTP site, ftp://ftp.globalvillag.com. Once you're running 2.5.5, choose "V.42" in the TelePort control panel, and use the initialization string listed above, and you should be OK. (Some Performas are currently shipping with GlobalFax v2.5.4P; this version should also have no difficulties.)
Q: I am trying to use Eudora with my Apple PowerBook Express modem but Eudora never dials out; sometimes Eudora reports that the serial port is already in use. What do I need to change?
A: Disable Apple's fax software upon startup and then use Eudora. You can use any Extension manager to accomplish this. Also, if you are using any version of Eudora prior to 2.0.2, make sure that you have selected the Apple Modem Tool and not the Express Modem Tool as your connection method. Using the Apple Modem Tool v1.5 is highly recommended; note that you will have to install 1.5 separately if you are not using the ACS Connectivity Package installation of Eudora. AMT 1.5 is available over the campus network. Check the "Computer Stores" zone and log on as "Guest" to the machine named "CCS bbs." (If you're using the version of Eudora 1.5.3 which comes with the ACS Connectivity Package, you should be using the Calyso tool instead.
Q: I'm trying to connect to the Sun Cluster at 753-0975 with my high-speed (>9600bps) modem, but I can't... I get garbled characters/hung connections/carrier loss/just can't get through... How can I fix this?
A: We've got a very baroque setup here. In order to connect, you must have your software give your modem an initialization string which forcibly slows it down to 9600bps and turns OFF any data compression. In addition, if your modem supports V.42 error correction, you should turn that ON -- just remember that V.42 is NOT the same as V.42bis! We've assembled a collection of initialization strings for several commonly used modems; it's at the top of the Eudora section, above. Please note that for a Global Village TelePort Gold II purchased or bundled with a machine prior to October 1995, may also need to upgrade your GlobalFax software -- contact Global Village at 408-523-1050 or by email at techsupport@globalvillag.com for details.
Q: I can connect to Kimbark (753-0975) but once I connect I just see garbage on my screen. What is happening?
A: Your data settings are probably incorrect. Double-check to make sure that you have set your communications program to use 7 data bits, one stop bit, and even parity when calling Kimbark. If you are using ZTerm to connect, type "term download" without the quotes at the first cc-tip> prompt. Then log on to your account. Then click on the "E71" in the bottom left of ZTerm's terminal window and change the settings from E71 to N81. You can now use sz to download files from your directory to your computer.
Q: What file transfer protocols exist on Quads/Woodlawn/Ellis/Kimbark?
A: Kermit, also X/Y/Zmodem - on the Unix side, issue the commands sx, sy, or sz for downloading; rx, ry, rz for uploading.
Q: I know how to log on to Kimbark; I've set my 14.4K modem to communicate at 9600 bps when calling 753-0975; I know that my cable supports hardware flow control; and I've checked the internal settings of my modem against ZTerm's configurations. Yet, when I try to transfer a file from my Unix account using ZModem, I get excessive numbers of errors, retransmits, and often I have to cancel the download. How can I fix this?
A: This situation is explained in Leslie Jones' excellent "ZTerm FAQ," available from ccsgopher.uchicago.edu; here is what you need to do:
To begin with, set ZTerm to 7 data bits, one stop bit, and even parity when you call 753-0975. You will see CONNECT "9600, 2400..." after which you enter a Return or two. After the logon banner which mentions the new modems, you should see cc-tip>. Type "term download" at this first cc-tip> prompt. You will then get a second cc-tip> prompt that will allow you to enter Kimbark, Ellis, or Quads. Enter your User id and password. Now you need to click on the E71 which appears along the lower bottom left of ZTerm's terminal window and change the setting to N81 to match the "term download" parameter you entered a moment ago. List the files in your directory and highlight and copy the name of the file you wish to download.
Then, from the Unix prompt enter:
sz -w [window size; some multiple of 512, such as 1024] filename
or you can try this:
sz -brew 2048 filename
-bre = Binary, Resume aborted transfers, and Escape all control codes
or on text files you can try:
sz -Zw 2048 filename
The file transfer should begin automatically as long as you have set a default download folder in the ZTerm settings menu. Here are additional commands that you might want to use when issuing the sz command:
Q: I have an Apple PowerBook 170 with a 2400/9600 data/fax modem and I can't get the fax function to work properly.
A: Apple's Fax software suffers from a number of flaws. One such flaw involves the Fax prefs file (found inside of the Preferences folder, which is inside of your System folder) becoming corrupted frequently. Try deleting this Prefs file and restarting your PowerBook. If your fax software icon still shows up with a large "X" drawn through it, you may need to upgrade your fax modem software. Find a copy of the Express Modem 1.1.2 (or later) installer image (the GeoPort Express Modem 1.2 installer or Apple Telecom v2.3 or later will also work). Transfer this image onto a blank floppy disk and restart your Mac. Hold down the Shift key during the startup process until you see a "Welcome to Macintosh: Extensions Off" message. Now insert your Express Modem software disk and click on the Installer application.
When you are finished, restart your machine and open your System folder. Remove the Express Modem control panel from your Control Panels folder and trash it. If you used the GeoPort Installer, trash the various GeoPort files found in the Extensions folder of your System folder these files are not needed by your PowerBook 170. You also should check to see that the "Serial Modem" tool is in your Extensions folder. If you can't find the Serial Modem tool, you may download a copy from the Computer Stores' file server (in the "Computer Stores" zone, machine "CCS bbs"; log on as "Guest" to the volume "Files"). The Serial Modem tool is used by your Fax software. Remember to save a copy of your Fax Addresses book before installing the new software. You can replace the new blank address book with your old one once you have completed the software installation.
Q: I just purchased a Power Macintosh model and want to take advantage of the built-in GeoPort Telecommunications technology. What else do I need?
A: You need to purchase a GeoPort Telecom adapter. Newer adapters, which include a hardware fix and the updated GeoPort software for PowerMac machines, can be special-ordered from CCS under the Apple part number M5438LL/A. Older adapters for AV machines (part number M1694LL/A) should also work with PowerMac machines as long as you install the new GeoPort v1.0 or later Power Macintosh software (or Appple Telecom v2.3 or later), which is available over the campus network from the Computer Stores' file server (in the "Computer Stores" zone, machine "CCS bbs"; log on as "Guest" to the volume "Files").
Q: Can I use my GeoPort adapter to connect to America Online?
A: Yes, but first you may need to check the following settings. Go into your Control Panels folder and double-click on the EXPRESS MODEM Control Panel. Make sure that the "Express Modem:" option is set to "ON", and that the "Modem Port Setting" option is set to "Use Express Modem". Also, check your Speech Setup Control Panel setting to be sure that "Speech Recognition" is set to "Off". Finally, you may need to change AOL's default modem initialization string. Begin by loading America Online and clicking on the "Setup" button. On the next screen, click on the "Edit Modem Strings" button and you should see a screen with three boxes for modem strings. Try using one of the following in the box labeled "Modem Initialization String":
AT&F&K0&Q0
or
AT\N1&Q0
Do not add extra spaces and make sure that the command is entered in all upper case letters. Use the numeral zero, not the letter "o".
Q: I thought my GeoPort adapter could function at speeds up to 14,400bps, but my Apple manual clearly states that this adapter will only work up to 9,600bps. What gives?
A: If you have installed the latest version of the GeoPort adapter software, your GeoPort will comfortably support not only 14.4K connections, but will go all the way up to 33.6K. Older versions of the GeoPort software would not support this higher connection rate, and thus the manuals and menus refer to a top rate of only 9,600bps. The current version of the software is "GeoPort-EM 3.1.1", and can be downloaded from Apple's web site.
Q: I am trying to use ZTerm with my GeoPort adapter. The adapter is connected to my Power Macintosh. I can never logon properly. What's wrong with my ZTerm setup?
A: First, set the "Express Modem" Control Panel to "Use Express Modem". Set the port as the Modem port (not the Printer port). Please note that ZTerm (any version up to 0.9x) currently does not recognize the PROTOCOL and CARRIER messages. If ZTerm receives either of these messages after a connection to a remote host, ZTerm interprets these strings as a failed dial attempt. The simple workaround to this problem involves adding "W0" to your initialization string. Insert "W0" immediately after the "AT" in your normal ZTerm modem string, as in "ATW0...". You can also 'hack' ZTerm with ResEdit so that it recognizes these strings. Open a copy of ZTerm an find the STR# 1000 resource. Add the following:
iCARRIER iPROTOCOL iCOMPRESSION.
The small "i" tells ZTerm to ignore the specified response during dialing.
A: Go to the Chooser and highlight the FaxPrint icon. Then click on the "Setup" button on the right side of the Chooser. Now scroll down to the bottom of your screen where you see the "Modem init" string icon. Replace the default modem init string with this string:
AT&FEV&H2&I2&A0S36=0
note the I2 = the letter "i" and the numeral 2.
A0 = A and the numeral zero.
Check to make sure that DIP switch number one (located on the back of your modem) is in the "DOWN" position. If you are using an "AV" machine, upgrade your version of FaxSTF to v2.6.1. The updater is available from the Computer Store server. If you are using a Power Macintosh machine, you can try v2.6.1 but will most likely have to upgrade to v3.0 of the FaxSTF software before the fax functions operate correctly.
Q: My Global Village Modem does not appear to be working correctly. Who should I call for help?
A: You can certainly call either our Service or Tech Support line, but it may be faster to call Global Village's Tech Support directly at 408/523-1050. Global Village will step you through a couple of procedures which will test the basic functionality of your modem. If Global Village determines that your modem is suffering from a hardware failure, they will authorize a replacement unit to be shipped via Federal Express to your address. This procedure is often faster than having the Campus Computer Store call Global Village for you and act as an intermediary. Global Village's repair department has determined that over 40% of all modems returned by customers as "defective" actually work fine - the end-user's communication software is set up incorrectly. Misconfigured communications software accounts for the majority of problem modem calls which the Campus Computer Stores receives. Please consult ACS's Resource Guide and the Eudora Questions and Answers document for specific help pertaining to accessing Quads/Woodlawn/Ellis/Kimbark. If you need software upgrades from Global Village, you can retrieve them from the Computer Stores' file server (in the "Computer Stores" zone, machine "CCS bbs"; log on as "Guest" to the volume "Files"), or you can ftp the latest software releases from ftp.globalvillag.com or http://www.globalvillag.com/.
Q: I just got the PowerPC Upgrade for my 500 series PowerBook, and now my internal Global Village modem keeps claiming it's not a PowerBook any more... What's wrong?
A: You must upgrade your GlobalFax software to version 2.5.5. The update is available from Global Villages web site, or from the Computer Stores' file server (in the Computer Stores zone, machine CCS bbs; log on as Guest to the volume Files). Note that if you currently have a version of GlobalFax prior to 2.5, you must purchase the 2.5 upgrade from Global Village before upgrading to 2.5.5; contact Global Village directly for upgrade information.
Q: I'm having trouble connecting my Global Village TelePort Gold II modem to the University dialup over SLIP; the connection just won't go through.
A: Check your Control Panels. If you have a "TelePort Serial" control panel (as opposed to a "TelePort" control panel), you need to upgrade to version 2.5 of the GlobalFax software; contact contact Global Village at 408-523-1050 or by email at techsupport@globalvillag.com for more information. If you have a "TelePort" control panel, your problem is probably an initialization string or configuration; contact the ACS Techline at 702-3111 for help.
Q: My older-model Global Village TelePort modem does not work properly with my Power Macintosh, why?
A: Versions of the Global Village Fax software previous to v2.08a allow you to only send faxes from a Power Macintosh. Contact Global Village at 408/523-1050 and purchase from them the upgrade to version 2.5.
If you are running System 7.1, be sure to install the "Hardware System Update v3.0" patch from Apple. This update comes on either two high-density diskettes, or a single 800K diskette for owners of older Macintosh models (Plus, SE). This update only affects System 7.1; it cannot be used on System 7.0.x or System 7.5. Global Village reports that HSU v3.0 fixes a few serial port problems on the Power Mac machines.
Q: I am trying to dial a number using my modem, but I never get dial-tone. What is wrong?
A: If you just got your modem, check the receptacles in the back of your modem. Usually there are two RJ-11 outlets - one for a phone handset and another for connecting the modem to the actual wall outlet. If these receptacles are not labeled, try switching the phone wire into the other receptacle and try again.
If, on the other hand, your modem has been working fine for months and suddenly your communications software keeps reporting "NO DIALTONE", your modem may have been fried by a power surge. It is not enough to plug the modem's power supply into a surge supressor; if the connecting phone wire extending from your modem is not also protected, a fatal surge can travel down that avenue during a storm or electrical surge. Power surges can occur under a variety of circumstances; it doesn't take an electrical storm to permanently damage your modem. If you buy an expensive modem, get a surge protector that includes two RJ-11 jacks. These are usually called ISOFAX or FAX line protectors.
Q: I keep getting the message "modem port in use" or "cannot find modem port". What's wrong?
A: Any of a large number of things, actually:
A: A modem expects to find an analog line when you plug it into a phone outlet. Plugging a modem into a digital phone system can damage the modem. Your options are to either have Telecom install a dedicated analog line (same thing as a line used by a fax machine), or purchase a "PBX adapter Kit". Alliance Peripheral Systems sells these units (they cost about $130 and they also come in handy when trying to dial out of hotels). These units do not convert digital to analog, but they do provide a safe means of using your modem in a PBX system. You may have to manually dial the phone number using your telephone set when placing an outgoing call. You cannot use your IBX line for both regular phone calls and data calls at the same time; when your modem is in use, callers will hear a busy signal when they dial your number. APS - 800/235-2753.
Q: I recently bought a used high-speed modem that I would like to use with my Macintosh computer. The cable that came with this external modem doesn't fit the serial port on the back of my Macintosh. Where can I get a cable that supports hardware-handshaking?
A: CCS sells this type of cable (MAC-MODEM-6).
Q: What is a modem script?
A: Most commercial communications programs, and many shareware ones as well, provide a way to automate routine data calls. A script usually initializes your modem, sets your communications software to the appropriate settings, dials a preset phone number for a specific service, and then navigates the system prompts by auto-entering your User ID and password after a connection has been made. This process speeds up the mundane task of manually entering this information over and over each time you call CompuServe, a BBS, Kimbark, or other online service.
Q: I have call waiting and it is interfering with my data communications sessions. How can I disable call waiting?
A: Add "*70" without the quotes to the beginning of your modem's initialization string. If you have a rotary phone instead of a touch tone phone, substitute "1170". This will disable call waiting for the duration of your call. An example dial string would look like this: "atdt *70,7530975". A directory listing should look like "*70,7530975". (For unclear reasons, the prefix for disabling call waiting was changed in some Chicago suburbs during the spring of '95; if you are in one of these suburbs, then substitute the appropriate prefix for "*70".
Q: I will be pursuing my studies overseas next quarter. Can I use my modem overseas? What sort of adapter will I need to accomplish this?
A: Please refer to the long text document, "Using modems overseas" at http://www-ccs.uchicago.edu/technotes/. This discusses the problems which you will face and how you can get around them. If you want to purchase an adapter kit right away, call Unlimited Systems Corp. at 800/275-6354.
Q: How can I improve upon Kermit's binary file transfer performance between C-Kermit and MS-Kermit v3.13?
A: Make sure that your modem is set up for hardware flow control (RTS/CTS). If you have 16550AFN UARTs, set your port rate to 57,600bps for V.32bis modems. Use two window slots and medium-sized packets; if Kermit fails to use more than one slot, try decreasing the packet size. For C-Kermit, you need to SET TRANSFER CANCEL OFF so that Control-C will not be interpreted as a transfer cancellation. Use TERMINAL DOWNLOAD as this adds more buffer memory to your session and also turns off all the escape characters. Use shorter packets if you experience flow control problems.
Q: Someone is trying to call my modem so that they can send me a file, but my modem never answers. What's wrong?
A: Check S-Register 0 (zero). S-Register 0 must be set to some value greater than zero before it will answer the phone. A value of two would enable the modem to answer the call on the second ring. From within your communications program, type "AT" without quotes and hit Return. You should see an "OK". Now type ATS0=1 and hit Return. Your modem's Auto-Answer light (AA) should immediately light up. Your modem will now answer the next incoming call on the first ring.
Q: What other documents do you recommend?
A: The ACS Resource Guide; The ZTerm FAQ from Leslie Jones; The LineLink FAQ; and Bernard Aboba's "Online Encyclopedia," which may be ordered from the Berkeley Macintosh User's Group -- or call 800/776-2684. The comp.sys.mac.comm FAQ, which is updated regularly, also serves as a good introduction to communications issues. If you want to be kept up to date on emerging modem technologies, Bulletin Boards, and various electronic networks, call BoardWatch Magazine at 800/933-6038 and get a one or two year subscription. You will not regret a subscription to BoardWatch. Also, visit a bookstore which has a used computer book section and look through the various tomes on modems and online services.
Kermit discussion - Columbia University's guide to using their dial-up modem bank; comp.sys.mac.comm remarks made by Frank da Cruz (fdc@fdc.cc.columbia.edu).
ISDN, xDSL, cable modems, 56K modems - the various web pages cited in those sections of this document, plus PCWeek magazine and the 56K Home page at http://www.56k.com/.
ATS7=120
Note that although any Hayes-compatible modem will support S-registers, there is often a great deal of variance in what S-register corresponds to what setting.