by Jon Loveless
Did you ever think about what a computer really is? Take the ATARI for example. With 48K bytes of memory it can store about the same amount of text as a 15 page document. An ATARI diskette can store about 40 more pages. You can think of your display screen as a "window" through which you can seen this information, about one quarter page at a time.
What's the point? Well, the time is here when, for the price of a cheap suit, you can expand your computer's access to millions of pages of memory, instead of just 40 or so.
We are talking about the MODEM. Let's de-mystify the modem, explore what it is, what it does, and then look at a few modems available for the ATARI.
Here are some terms you will find in the world of modems:
MODEM--The word derives from "modulate-demodulate." A modem is a hardware device that translates an incoming sound signal (frequency) into a binary code that your computer will understand. (Computers do not understand sounds). The modem also works the other way around. It will translate an outgoing, computer-generated binary code into frequencies that can be transmitted over circuits used by the telephone company.
BAUD--This term describes the rate at which data is transmitted. The telephone company has established 300 baud as a standard rate of data transmission for phone lines.
This equals 30 characters per second or approximately 350 words per minute. This is about as fast as most people can read. There is also a 1200 baud standard rate available on the phone system, at a premium price. Watch for this price to fall over the next few years.
ACOUSTIC-COUPLED--This describes the type of modem that transmits and receives directly through the standard telephone receiver. This kind of modem has two foam "cups" into which the earpiece and the mouthpiece of the receiver are placed. The cups channel the sound, audible as a high-pitched whine, to and from the phone system, and muffle extraneous noise.
DIRECT-CONNECT--This is the newer breed of modem. It can connect directly to your telephone wall jack or plug into your telephone with a "Y" adapter. Outside sound interference and clumsy manipulation of the receiver are eliminated.
ANSWER-ORIGINATE--These terms describe which modem is calling and which modem is answering. There must be a modem on each end, but they do not have to be the same brand. Either modem can do either job, but not at the same time.
By now, you may be interested in buying a modem, and wondering what features are important. Here are some things you should be aware of.
Acoustically-coupled modems, the "ear-muff" type, were the first on the market, and are still the cheapest. They have definite drawbacks. Stray sounds in the vicinity of the modem can and do leak past the muffs and can affect data transmission. Also, using the acoustical modem is awkward, since the correct end of the phone receiver must be inserted in the correct end of the modem. This sounds minor, but the error is easily and frequently made.
Still, acoustic modems do work, are inexpensive, and may meet your needs. Prices for direct-connect modems seem to be dropping, and the higher degree of reliabiltiy for them makes it difficult to recommend anything else. If you think you would be even a semi-serious "on-liner," you should think in terms of a direct-connect, plug-in modem. Your data will be cleaner, and the benefits of uploading and downloading data over networks, with the new information utilities (see separate article, this issue), or with other individuals, will repay the extra investment.
Some modems have "status indicators." When the modem is in use it is often important to know what the status of your connection is. Is the modem "ready?" With a direct-connect modem, is the simulated "receiver" on the hook or off the hook? Has there been an accidental disconnect? Is the other end answering? The more infor ation provided by the modem's status indicators, the better.
Some modems have "autodial/autoanswer." You can dial a phone number from your ATARI keyboard! Admittedly, this is a luxury, but if you use a modem a lot, it is a nice feature to have. Autodial allows you to store telephone numbers in your software program, and have the modem do your dialing for you. This eliminates the need for a telephone near the computer, as long as you have a phone cable long enough to reach your telephone jack.
Autoanswer is only needed for the serious application of data communications such as operating a bulletin board service, or otherwise responding to the incoming call of another computer. Think of the possibilities, though! You can call your own computer from any remote terminal, or even from a phone booth with one of the miniature modem-terminals recently announced. Other features to look for include:
- compatibility with the Bell 103 Standard;
- full-duplex and half-duplex (in case you only want to send or receive);
- 300 baud rate, 1200 baud optional;
- RS-232 plug compatibility for ATARI 850 interface connection;
- proper connecting cables!
A word about cables is in order. Modems must be connected to your other equipment, and to the telephone line. You would think that an expensive item like a modem would come with the appropriate cables. Not always so, and the price difference between a more expensive unit with cables and a less expensive one without, may be misleading (some cables cost $50!). Also, some modems are designed to hook up more simply, eliminating some cable requirements. Before you buy, determine your complete system requirement, and compare the price for all pieces. You will want to include software costs, too, (see separate article, this issue).
All modems, once the proper connections have been made, will perform their primary function of data communications, so the bottom line in any decision should be--quality, price, and extra features. You will probably find your use of a modem will be greater than you now expect, so be open to the more capable units.
Any modem can work with the ATARI, if properly connected, but some have been built specifically with the ATARI in mind. We will discuss the principal ones here.
ATARI 830 MODEM ($199.00)
The ATARI Modem, sold by ATARI, is a "Novation 'CAT'" modem in ATARI dress. It is a standard acoustically coupled modem with only very basic features. It is fine for a beginning user, or someone with limited needs. Since it is marketed as an ATARI product, it comes with all required cables. It also needs the ATARI 850 Interface, which some modems do not, so if you don't have the Interface you should seriously consider the Microconnection modem (see below), or others that bypass the Interface.
The ATARI 830 is a plug-in-and-go product with good documentation. You will need software with this, as with all modems, and might well consider ATARI's TELELINK cartridge ($30) for a nice, modular system. Caution! TELELINK is a very limited program, and will not allow copying to disk. It will drive the ATARI printer, but printing "on-line" is expensive. The major drawbacks with the ATARI 830 are that it is acoustic, and has limited features.
An alternative buy would be the "Novation 'CAT'" if you can find cables. Two other "Novation" modems are compatible with the ATARI. One is the D-CAT, a basic direct-connect model, and the AUTO-CAT, that has the autodial feature mentioned earlier. Although not considered in depth here, they are both good products that should be considered as in the running.
MICROCONNECTION-A ($199 to $328)
This direct-connect modem is made by the Microperipheral Corp. and comes in four versions all designed for the ATARI. This selection is very attractive to the prospective buyer.
For example, there is a buss-decoding version ($249) that allows connection without using the ATARI 850 Interface. This modem can be used with as small a system as the ATARI 400 and the 410 cassette recorder. This model has a DB-25 socket that allows connection of the ATARI printer, again without Interface. This makes the Microconnection a good candidate for a small basic system. For $79 more this model comes with autodial.
There is a plain version ($199) that does require the Interface, and for an additional $79 you can get the autodial and autoanswer features.
Caution! Microconnection's autodial uses pulse dialing (not touch tone) which cannot be used with the MCI or SPRINT long distance phone services, but you can manually dial SPRINT or MCI with this modem. If you are a heavy user of these long distance services this could be an important limitation.
Microperipheral has done a commendable job of supporting the ATARI, and their own software enhances the capability of their modem dramatically. The top of the line software, called TSMART ($79.95) incorporates autodial as well as message preparation and storage features that reduce expensive "on-line" connection time. You will appreciate this after you see your first phone bill after buying a modem.
The Microconnection is relatively simple to connect and use. It comes with extensive, if dense, documentation which includes a listing of free bulletin board services, by area code (a nice touch!). Microperipheral Corp. maintains a user service accessible through Compuserve, over which you can get updates of their software. Now that's service!
This is a direct-connect modem by Hayes Microcomputer, Inc. Although it does not come as a model specifically for the ATARI, you can purchase a cable to connect it to the ATARI 850 Interface (required). The fact that this modem does not come with a cable is a serious drawback in a product that costs so much. This is not a criticism of Hayes alone, as you will discover when you buy your first non-ATARI printer, or other peripheral device.
Assuming you buy the "Hayes Stack," as it is also known, and are able to get or make a cable, you will have the most flexible modem in the price range. This is truly a "smart" modem. The heart of the device is a 28 microprocessor with a 2K byte control program built in. The only switch is an ON/OFF toggle! Everything else is program controlled, or preset by you, utilizing the configuration panel under the front cover.
Here are some of the features of the SMARTMODEM:
- either touch-tone or pulse dialing at any time;
- audio monitor allows you to hear what your phone line is doing (a status indicator, and a real help when the receiving party is busy)
- storage of the last number dialed;
- automatic redial (helpful for disconnects, busy signals, etc.);
- seven LED status indicators on the front panel (impresses visitors);
- complex dialing sequencing (eg. dial number, wait for tone, send ID, dial another number, as required for MCI and SPRINT);
- programmable in any computer language and compatible with most data communication software.
The list goes on, but the point is made. The Hayes SMARTMODEM is very versatile, but suffers due to a lack of direct applicability to the ATARI. With the appropriate cable (I made my own) and almost any good terminal software, this modem is the most flexible.
There are other usable modems around, though not specifically for the ATARI. They will work fine with the proper cable, and some of the good software. If you are not in the market for a modem now, l guarantee that you will be some day. It might be a good idea to wait, if you have no immediate urge to link up with the rest of the tribe. Prices keep coming down, and good gear gains reputation as satisfied users swap notes.
Keep your eyes open for new, low cost entrants to this field. For example, l noticed (but have not used) the SIGNALMAN MK-1 from "Anchor Automation" at an unbelievable price of $99, including RS-232 connector cable. This direct connect modem could be the forerunner of a price revolution.
Meanwhile, the modems we have discussed are definitely state-of-the-art products and can be expected to provide good service for a long while.
And so we complete this introduction to the modem, a simple device that opens to you a whole new world of information.