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If you're still working in Windows 3.x, you can't keep more than one communications or fax program running at a time. There *is* something you can do besides upgrading or running comm apps alone. A utility called KingCOM 2.0 (as well as a host of similar shareware apps) will allow you to free up the COM port when one program's done with it, so you can move on to the next.
Ever had Call Waiting bounce you out of a modem connection? Use the prefix *70 (or 1170 in some locations) to turn off Call Waiting. This command only lasts for the duration of the current phone call, so call waiting will automatically resume once you've finished your on-line work.
If you're tired of changing the settings every time you take your laptop somewhere new, use Windows 95's HyperTerminal to set up separate sessions for your usual haunts. Once you've set up a connection from work, home or Grandma's house, you can connect with just a double-click on the appropriate icon.
So you hooked up your brand-spanking-new V.34 modem and discovered your transfer speeds didn't improve much? There are two potential culprits: the speed of the COM port and the manner in which Windows 3.x handles communications. If your COM port isn't of the Enhanced Serial Port variety or isn't based on a 16550 UART chip, you probably won't get past 9600bps. If your serial port *is* based on a 16550 UART, Windows itself is probably the culprit. You'll need a high-speed port driver or a new communications driver. One that's highly regarded for Windows 3.*x* is TurboComm, which replaces your basic Windows communications driver. Warning: Some third-party communications programs also replace COMM.DRV with their own custom drivers. Make sure you're not upgrading needlessly or causing a conflict between rival replacement drivers.
Don't confuse *connection speed* and *effective throughput*. Connection speed governs how many characters are sent across a connection in a given time. Effective throughput is how much data will actually be transferred after data compression is figured into the equation. A V.34 modem can transmit 28,800 bits per second, but the effective throughput may be 115.2 Kbps. The larger and more compressible a file is, the better throughput you'll get. You'll almost never see throughput as high as the manufacturer's rated maximums, so don't panic if your actual results don't come close.
If you're working in Windows 95 and you have a 16550 UART chip governing your serial ports, make sure you're getting your modem's worth. Click Control Panel and select Modems/Properties, then look under the Connection tab for Port Settings. Check the "Use FIFO buffers" option and drag both sliders all the way to the right.
High-speed modem users (14.4Kbps and above) should ensure that they get the best possible connection and throughput by clicking on the Start menu, choosing Settings/Control Panel/Modems/Properties/Maximum Speed and selecting 57600. Click the Connection tab. Click Advanced and check off "Use error correction" and "Required to connect" in the upper-right hand corner of the Advanced sheet. Save everything.
The "Extra settings" line in the Advanced screen mentioned above can add any AT commands you know need to be passed to the modem that aren't already covered.
If you're not sure your modem is responding to your commands, go to the Start menu, and choose Settings/Control Panel/Modems/Diagnostics and select your modem's COM port. Choose More Info. In short order, you should get a list of commands and responses from the modem. If you get an empty list, or an error, check your physical connections and port and IRQ settings for your modem.
Almost every state-of-the-art modem on the market offers some sort of user upgradability, generally achieved through the use of Flash (software) upgrades. This gives you a way to upgrade your modem without physically fiddling with the hardware, but even a minor electrical surge can wipe the modem's memory. If this happens to you, call the manufacturer's support line or BBS and request the most up-to-date version of the Flash BIOS for the modem.
Avoid dropped characters on high-speed connections by using the Xon/Xoff protocol for your transmissions. This forces the port to wait for an OK before trying to process the buffer-load of data. In Windows 95, you can find this option by choosing Start/Settings/Control Panel/Modems. Select your modem in the list box, click on the Properties button, choose the Connection tab and click on the Advanced button. That will bring up a window with options including the Xon/Xoff protocol. In Windows 3.x, click on Control Panel/Choose Ports, click on the appropriate COM port, and make the same changes.
One fact that many do not realize: If a modem is placed near a fluorescent light of any sort, the modem connection will experience intermittent line failures and losses of data. So if you have a desk lamp with a fluorescent bulb, position it a good distance (several feet) away from your modem.
Just because your modem's manufacturer claims the device is Hayes-compatible, don't assume that means you'll connect at maximum speed all the time. Today's modems automatically fall back to a lower speed if the line noise is too intense to maintain a faster connection--but sometimes they fall back too soon, or too far. Search for the value "S36=" in the initialization string. Check your modem's settings against your manual, and if your modem will accept it, change that setting to "S36=7," which is the default for Hayes-compatible modems. This will force your modem to try connecting at high speeds in two different ways before dropping back to a standard asynchronous connection with automatic speed buffering.
For high-speed modem connections under Windows 3.x, set the serial port to use hardware handshaking (CTS/RTS) by going into Control Panel/Choose Ports, clicking on the proper port, then selecting Hardware under Flow Control.
Sometimes, you need to log in to an on-line service or BBS using a plain ASCII interface. Here's the proper settings for some of the more popular services and networks:
CompuServe: VT100, 7E1, full duplex
GEnie: VT100, 8N1, half duplex
TymNet: VT100, 8N1, full duplex
SprintNet: VT100, 8N1, full duplex
Most BBSes: VT100, 8N1 or 7E1, full duple
almost all Internet sites: VT100, 8N1, full duplex
(Both Prodigy and AOL auto-configure, so you can't reset the settings.)
Most external modems have a set of status lights that tell you something about the existing connection. Here's what some of them mean:
*CD—carrier detect.* Shows whether the other end of the connection answered.
*AA—automatic answer.* The modem will pick up all calls until you reset it.
*OH—on hook.* This tells you your modem's line is available for connections.
*SD—send data*, also seen sometimes as TX—transmit. Shows that your modem is sending data.
*RD—receive data*. Your modem is transmitting data back to your system when this light is on.
If you have an internal or PCMCIA modem, but you want status lights, try using one of the many shareware software modem light programs. These are tiny applets that sit on your desktop and simulate the lights on the front of an external modem.
If you actually have more than four comm ports on a Windows 3.x machine, you'll want to make sure the system recognizes all of them. In the SYSTEM.INI file, make sure the MaxComPort= setting has the correct number of serial ports listed.
To test that your modem is functioning, go to the DOS command line in Windows 3.x or Windows 95 and type ECHO ATDT >COM*x*, where COM*x* represents the port you're testing. If you're trying to test COM1, for example, type ECHO ATDT >COM1
" If you hear a dial tone, it's working just fine. To cancel the dialtone, type ECHO ATH >COM*x*.
The speed of a modem transfer is not determined simply by the modem's connection speed and the amount of compression. Some transfer protocols just work faster than others. The fastest we've encountered is Zmodem, which comes with just about every communications package on the market. It also allows you to resume a download right where you left off if your connection gets interrupted for any reason.
Under Windows 3.x, sometimes a modem just won't reset unless you flip it off, then on again. If you want a way to force that modem to reset after each connection, add AT&F to its initialization string in all of your communications programs. This command resets the modem to factory defaults, clearing any changes you may have made.
If your modem uses the MNP5 compression protocol and you're having trouble connecting, try deactivating that protocol. When MNP5 is used in a connection to a modem without MNP5 capability, it often causes flow control problems.
One of the more insidious causes of modem failure among traveling computer users is the humble digital PBX phone line. Those lines carry an actual electrical charge, which can surge and fry your modem's innards if you plug your modem directly into the wall. Don't just use an RJ11 cable—consider buying an acoustic coupler designed specifically for PBX lines.
One of the notable problems with modem communications is how quickly the various RJ11 and serial cables can become toasted after lots of hard use. Serial cables, especially, tend to go bad often. It's a good idea to keep a spare on hand. If you can't make a connection, try swapping out the serial cable for a fresh one.
If you have an internal modem and your comm program doesn't allow you to listen to a connection as it goes through, type ATD and you'll hear the entire connection sequence as it happens. Leave the modem speaker on when you're troubleshooting problems so you can watch the onscreen status reports and modem lights and compare them to the sounds you hear. You can tell if the connection is actually being made, then dropped at the other end, which can mean that the problem is at the other end of the line.
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