Classic Computer Magazine Archive COMPUTE! ISSUE 70 / MARCH 1986 / PAGE 54

Atari XM301 Modem

Tom R. Halfhill, Editor

Requirements: Atari 400/800, XL, or XE computer with at least 48K RAM and a disk drive. The 1200XL requires a slight hardware modification (see text).

If you've been waiting for a (nearly) painless way to get started in telecomputing, the new Atari XM301 modem might be just the ticket. For about a quarter of what a bare-bones acoustic modem cost just a few years ago, the XM301 package includes a reliable, 300 bits-per-second (bps), direct-connect modem with autoanswer and autodial; an easy to use terminal program with full upload/download capabilities; free introductory time on popular commercial information services; and a well-written manual that guides you step by step through the often-confusing world of telecommunications.

Thanks to the latest modem-on-a chip technology, the XM301 is just slightly larger and heavier than a pack of cigarettes. And that includes the power supply and interface, because the XM301 doesn't require a power supply and interface—it plugs directly into the Atari's serial input/output (SIO) port and draws its power from same. This is a major improvement over early Atari modems, which forced you to buy the $200 850 Interface Module and add yet another power transformer to the existing clutter.

Hooking up the XM301 takes just two steps. First, plug its permanently attached serial cable into the SIO port. Second, unplug the modular phone cord on your telephone and connect it to the XM301's modular jack.

The only complication is if you're using a 1200XL computer. The 1200XL designers wanted to discourage manufacturers from making peripherals that drew power from the computer, so they added a current-limiting resistor to the SIO port which keeps devices such as the XM301 from operating properly. Fortunately, the fix is not difficult for an Atari service technician or experienced electronic hobbyist. According to Atari, resistor R53 on the SIO port must be bypassed or replaced with a jumper. Atari recommends that you take your 1200XL into an Atari service center for this modification. (It won't affect any other operation of the computer.)

Upload And Download

Once the modem is hooked up, you're ready to run the terminal software included in the package, XE Term. Despite its name, XE Term works on 400/800 and XL series computers with at least 48K RAM as well as on the newer XE machines. The disk includes DOS 2.5 and an autoboot file that automatically runs XE Term when you switch on the computer.

Pop-up menus and single-keystroke commands make XE Term extremely easy to use. Yet it's not a stripped-down terminal emulator; it's actually a fairly versatile program that contains enough features to satisfy most people's telecomputing needs. Earlier Atari terminal programs, such as the TeleLink I and TeleLink II cartridges, often were criticized for their lack of file transfer functions. XE Term is a sharp departure from the TeleLink series. Not only does it allow you to upload and download files with other computers, it even provides three different protocols (file exchange schemes) for this purpose.

The simplest protocol is the ASCII transfer function. It's most often used for exchanging text files, such as documents created with a word processor. You can also "capture" any incoming text with this option and send it to the disk drive or printer. ASCII transfers don't employ any error-checking, however, so characters can get garbled if the phone line is noisy.

The second transfer protocol in XE Term is called XMODEM, a standardized scheme that is popular on many electronic bulletin board systems (BBSs). XMODEM is somewhat slower than ASCII protocol, but it checks for transmission errors during the transfer. This makes it particularly useful for uploading and downloading such critical files as programs.

XE Term's third transfer scheme was a surprise—the A-protocol used by the CompuServe Information Service. XE Term's automatically recognizes A-protocol, so it's easy to download programs and other files from CompuServe.

The only drawback to XE Term's file transfer capabilities is its rather small buffer—only about 14K. Most Atari terminal programs have larger buffers. This restriction means that files longer than 14K must be broken up into pieces before uploading or downloading.

Online Phone Book

XE Term strikes a balance between ease of use and full-featured telecommunications. You can link up with Ataris, most other personal computers, information services, and BBSs of almost any flavor. But if the other computer is an oddball or a mainframe with unusual requirements, you may need a program that provides more communication options.

To reach XE Term's Options menu, you press O from the main Functions menu (a keystroke that Atari forgot to list on the Functions menu, by the way). The Options menu pops up and lets you change the input parity (none, even, odd, or clear); output parity (none, even, odd, or set); the duplex mode (half or full); and translation mode (ASCII and Atari ASCII, called ATASCII). You can also change the left screen margin from its normal indentation of two characters.

A few convenience features make XE Term even easier to use. You can save the communication settings to disk in a configuration file so the program always boots up the way you want it to. A dialing menu lets you switch between tone and pulse dialing, store up to five phone numbers that can be dialed with a single keystroke, or dial directly from the computer keyboard. When you're establishing a connection, all telephone sounds are routed through the TV or monitor speaker. That way, you can listen to the modem dialing the number and hear any busy signals, recorded messages, or humans that may be encountered on the other end of the line.

Automatic log-on sequences can be programmed to speed up access to remote computer systems. For instance, you can tell XE Term to dial your local CompuServe access number, type a CTRL-C to get CompuServe's attention, and enter your ID number and password—all without any intervention on your part. You can also set up the modem for autoanswer mode in case someone wants to call your computer.

A Few Extras

The 50-page manual is very well-written and contains just about everything you need to know to use the XM301 modem and XE Term. There's even a short glossary of telecommunication terms. For advanced users, a file on the XE Term disk contains technical information about the modem and its software interface. Another disk file, HANDLER-.OBJ, is the modem's device driver. This makes it possible for programmers to write their own custom terminal or BBS software for the XM301.

On top of all this, you get introductory offers to online services and discount coupons that by themselves are worth more than the cost of the XM301 package. There's $15 worth of free time on CompuServe, a $20 discount for joining The Source, a $75 password and hour's time on Dow Jones News/Retrieval, a $10 coupon for joining Dialog's Knowledge Index, and a free password and month's access to Dun & Bradstreet's electronic edition of the Official Airline Guides.

The Atari XM301 package is definitely one of today's best values in telecomputing.

Atari XM301
Atari Corporation
1196 Borregas Avenue
Sunnyvale, CA 94088