Classic Computer Magazine Archive ANTIC VOL. 7, NO. 2 / JUNE 1988


Atari SX212 and SupraModem 2400

Two breakthrougb values in online hardware

Atari Corp.
1196 Borregas Avenue
Sunnyvale, CA 94086
(408) 745-2000
For Atari 8-bit or ST



The SX212 ($99.95) is Atari's first 300/1200 baud, Hayes-compatible direct-connect modem. It will work with your ST or your Atari 8-bit computer-without any additional interface devices. - All in all, the SX212 is a safe, workable modern that offers Atari users an easy way to move up to 1200 baud online speed at the most affordable price on the market.

Best of all, the SX212 works fine! During hours of online testing at Antic, we did not have any problems with the SX212 power supply, a weak point of the Atari 1030 modem. Nor did we fmd any bare wire-tips dangling inside the case, as has been a worry to Atari XM301 modem owners (although it remains unclear if any equipment damage can be blamed on this threat).

The SX212 has a speaker, permitting you to hear busy signals, carrier tones and wrong numbers. If you've seen Atari's XEP80 eighty-column module (Antic, July 1987), you've already seen the SX212. Both were designed to use the same case. (This may explain why the silent XEP-80 has speaker brackets and a hole for a volume control. It also has recesses for eight modem status lights).

Atari SX212 Modem


Eight-bit owners have the option of connecting the SX212 in one of two ways. if you own an Atari 850 Interface or a P:R: Connection, you can connect it to your SX212 with a standard modem cable-and the SX212 will act like a Hayes modem. The Antic Technical Staff has successfully tested the SX212 with HomeTerm, Backtalk and 850 Express software.

If you dont own an 850 or P:R: Connection, you can connect the SX212 directly to your Atari "daisy-chain" with a regular Atari SIO cable-the same type of cable that connects your disk drive to your Atari. Unfortunately, the previously mentioned programs will not work with an SX212 connected this way.

Presently there are only a handful of modem programs which support the SX212 without an 850-compatible interface. Most of these are Public Domain AMODEM terminal programs that have been altered to work with the SX212. There are also public domain "patch" programs which will similarly modify commercial online software such as HomeTerm. Check your favorite BBS and CompuServe's SIG* Atari for the latest patches.\

Although the SX212 was first sold without software, future releases of the modem are to include the SX Express! program, the newest member of Keith Ledbetter's popular family of online software. An Atari spokesman says that as soon as their packaging contractor delivers the goods, SX Express! disks will be on sale along with an SIO cable for about $19.95.


Your SX212 will also work with your ST No special cables or adapters are necessary-just use a standard modem cable and plug it into the ST's modem port.

On the ST, the SX212 can be used with any terminal program which supports a Hayes-compatible modem. Using the ST, we successfully tested the SX212 with Flash and several types of VT-52 emulators. Finally, we used the SX212 and FoReM-ST software (Comnet Systems) to create and control a BBS.


Atari's SX212 modem appears almost suspiciously competent. The $99.95 SX212 uploads, downloads and runs a BBS as efficiently as Antic's Hayes Smartmodern 1200--which sold for $599!

But although the SX212 costs only a fraction of the Hayes Smartmodem, it is a bit more difficult to live with. The SX212 speaker volume control is located deep within the modem. You need a long, thin screwdriver to adjust it.

The status lights, which let you know what the modem is up to, are dim and difficult to see. Your eyes must be perfectly level with the modem to see any lights.

The SX212 only has one SIO port, so it must be placed at the far end of your chain of peripherals. Because of this limitation, you can't use the SX212 with any other single-port peripheral, such as a program recorder.

Documentation for the SX212 is adequate for a telecommunications novice, but there is very little for the serious programmer, and there is no documentation for the SX212's handier. The manual is a 51-page guide to installing the SX212 and using its command set.

Still, despite any imperfections, at only $99.95 the SX212 is an unbeatable value for any Atari computer owner.

Supra Corp.
1133 Commercial Way
Albany, OR 97321
(503) 967-9075 (orders)
(503) 967-9081 (technical support)
$199.95 with cables and software



The SupraModem 2400 direct-connect 300/1200/2400 baud modem has now been used extensively at Antic and we haven't had any trouble with this hardware except on 2400 baud uploads; and downloads, which can probably be blamed on the telephone line noise you'll inevitably encounter at 2400 baud.

The SupraModem 2400 is one inch high, 4 5/8 inches wide and 6 1/2 inches long. it can be stacked easily on the back of the SupraModem, from left to right, you'll find a nine-volt power jack, a female RS-232C serial port, a "line" socket for the provided telephone cable and a "phone" socket for your telephone.

The SupraModem 2400 comes with a 64-page manual that extensively covers the controls, commands, configurations, S registers, auto-dialing and auto-answering, diagnostic tests, result codes, FCC rules and more.

If you're running a bulletin board system, you'll want to know that the SupraModem 2400 automatically answers calls and hangs up afterward, and you can change the baud rate through software. The modem comes configured for automatic tone dialing, but it can also be set for pulse auto-dialing.

According to Supra Corp, the SupraModem 2400 is completely Hayes-compatible. It has a speaker with three volume settings-loud, Louder and PAINFUL! Unfortunately this is controlled through software, not with a volume knob. And if you put a pillow over the modem, you won't be able to see the front panel fights to tell what's going on.

The eight front lights are:
HS High Speed (2400 baud)
AA Auto-Answer mode
CD Carrier Detect
OH Off Hook
RD Receive Data
SD Send Data
TR Terminal Ready
MR Modem Ready

SupraModem 2400

Long, continuous use doesn't slow down the modem or cause other troubles in transmission and reception. I accidentally left the power on over the weekend and the SupraModem 2400 showed no signs of resulting wear.

My data line at Antic Publishing is shared with the editorial staff of Model Shopper Magazine, so obviously we can't both go online at the same time. However, if the SupraModem is on when Model Shopper goes online, through the Supra's speaker I hear the dial tone and the number being dialed. I never noticed this on the Avatex 1200 modem I previously used.

In the Atari areas of CompuServe and GEnie, opinions about the SupraModem 2400 thus far are mixed. Users either really like it or really don't. Many don't like the four-level volume control (three ons, and an off). A few have had trouble running bulletin board systems, but we didn't encounter any problems during our BBS tests. Not everyone likes the small case because their telephones won't fit on top of the modems.


I wanted to see how long it took to transfer data at 1200 and 2400 baud, using the SupraModem 2400 with Flash software. So I created a file of exactly 100,000 bytes and stored it on a 10 Mb SupraDrive hard disk. The file took 22 minutes and 33 seconds to upload at 1200 baud under XMODEM protocol. And it seemed as if it would need about 15 minutes at 2400 baud, but I never found out for sure. I'll blame line noise-not an unusual problem at that speed.

My first attempt sailed along until the modem tried to upload block 125. After 15 attempts, it aborted the upload. Each attempt took about 15 seconds, and six minutes were needed to get that far. The second attempt went well-all the way to block 704. The upload was aborted, again after 15 attempts, and this time it took about 17 minutes.

Overall, the SupraModem 2400 seems to be a good product. I wish I'd been able to come up with a complete transfer at 2400 baud, but for the price I don't think you can go wrong, even if you rarely expect to use this SupraModein at 2400 baud.