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This part of our series will be devoted to modems, mice, and sound cards -- three of the most important components in a multimedia PC.
In today's economy, it is essential that your PC be able to exchange information with other PC's easily and quickly. While this can be done by exchanging floppy diskettes with other PC's (a practice sometimes referred to as "Sneaker-Net" for obvious reasons), or by connecting PC's together with special cables and/or circuit cards (commonly referred to as a "local area network" or "wide area network," depending on the number of PC's involved), by far the easiest and most common way of connecting PC's is via regular telephone lines. The circuit card that performs this task is commonly referred to as a "modem."
The name "modem" is actually a contraction of the phrase, "modulator/ demodulator." This refers to the fact that, in order for computer data to be able to travel over telephone lines, it must first be translated, or modulated, into complex, warbling or gravelly-sounding audio tones that fall within the narrow range of frequencies that phone lines are designed to handle (from approximately 300 Hertz to 3,000 Hertz). At the other end of the transfer, the data must be demodulated -- that is, it must be turned back into the binary signals the computer's circuitry can understand and process. Without going into a lot of technical detail, suffice it to say that the current standard for PC modems is a maximum speed of 14,400 bits per second. A new generation of modems, capable of 28,800 bits per second-- twice as fast--is rapidly becoming popular. In either case, however, the modem should comply with the V.32bis and V.42bis standards set by the International Telecommunications Union (an agency of the United Nations that sets worldwide standards for telecommunications devices). In the case of a modem capable of 28,800 bits per second, the ITU's V.34 standard should be supported.
Since fax machines use regular telephone lines in much the same way modems do, it was only natural that modem manufacturers would begin incorporating fax capability into their products. As a result, the vast majority of high-speed modems now on the market also include fax technology. Unless you already have a separate fax machine -- and maybe even if you do -- there simply is no reason not to buy a "fax/modem," as these units are called. In such cases, you should look for "Group 3" capability to insure the best throughput, and to be able to communicate with most other fax devices.
Unlike most other PC-related devices, modems are available in both internal and external models. In other words, there are modems which are mounted on cards which plug into the PC's motherboard, and remain inside the computer, while others have their own case and power supply, and are connected to one of the computer's two serial ports by means of what is commonly called an "RS-232 cable." (RS-232 refers to a "Recommended Standard" of the Electronics Industries Association for connecting computers together.)
For a multimedia system such as we are assembling, an internal modem is the better buy, both because it takes up less space and because it costs less than an external model. We'll have more to say about modems later in this article.
We turn now to the subject of computer mice. Multimedia PC's, such as the one we are designing in this series, require the use of a special kind of software. This class of program is called either an "operating system" or a "graphic user interface." The term "operating system" denotes software that acts as a sort of "master control" over the use of the computer's components and resources. In contrast, the term "graphic user interface" is used for a program that works with the operating system, using graphic images or pictures (commonly referred to as "icons") to help the user make better use of the PC.
By far, the most common graphic user interface in use today is Microsoft Windows. A new version of this package, called "Windows 95," should be on the market by the time you read this. For our purposes here, it is enough to say that a true multimedia PC specifically requires the use of Microsoft Windows. A similar package, "OS/2" from IBM Corporation, is also rapidly gaining in popularity, and has many of the same features.
In order to make use of either OS/2 or Microsoft Windows, a special "pointing device," more commonly referred to as a "mouse," is needed. By using a mouse to "point and click" on a given program's icon, graphic user interfaces make it unnecessary for the user to type in complicated commands at the keyboard. This makes use of the computer's resources easier, faster, more efficient, and, ultimately, more productive.
There are two types of computer mice in general use today. One type, called a "bus mouse," uses a separate interface card plugged into the motherboard to communicate with the rest of the computer. The other type, known as a "serial mouse," accomplishes this task by using one of the computer's own serial ports. Both types of mice will work with either OS/2 or Microsoft Windows. The actual communication between the mouse and the rest of the computer is controlled by a special program called a "mouse driver." This software is generally packaged together with the mouse, along with installation and setup instructions. Generally, a serial mouse is slightly less expensive, so that's the kind we'll use in our example system. Right now, for instance, a Micrrosoft Serial Mouse can be bought for under $50, depending on where you shop.
Last but not least, we come to the sound card. The term "multimedia PC" refers to a personal computer that uses multiple media -- specifically, both sight and sound -- to impart information to the user. It should therefore come as no surprise that high-quality audio is required for this purpose.
The original IBM PC contained a tiny internal speaker whose primary use was for diagnostic purposes. In other words, it would beep at you in one way or another when you made a mistake, or when something went wrong with some part of the computer's hardware. For use in playing music or narration, however, it leaves much to be desired, to say the least!
As a result, over the past three years or so, a number of manufacturers have developed expansion cards which, when plugged into the motherboard and connected to a pair of speakers or an existing stereo system, provide excellent sound and music reproduction. By far, the leader in this segment of the PC industry is the "Sound Blaster" series of cards manufactured by Creative Labs, Inc.
At the time I write this, new developments in this area are coming fast and furious down the pike. One new trend does bear mention, however, as it has a direct bearing on the quality of the sound our example system will be able to produce.
That new trend is commonly referred to as "wave table" sound. In other words, the sound qualities of various musical instruments have been translated into digital information, or "digitized," then stored in special memory circuits known as "Read-Only Memory," or ROM. This type of memory generally cannot be erased or written to -- it can only be read from. This kind of technology is also used in electronic organs and synthesizers, which is why it is also referred to as "wave-table synthesis."
Because of the amount of processing power demanded by these cards, a fast 386, or, better yet, 486 PC is needed, preferably with VESA or PCI Local Bus, a large, fast hard drive, and plenty of RAM. Because wave-table technology is still fairly new, sound cards utilizing it are still somewhat costly.
At the time I write this, a Sound Blaster AWE 32 sound card costs around $220 to $250. Naturally, less powerful models are considerably less expensive.
By this time, if you've been keeping track of the cost figures I've mentioned, you may be getting a little concerned about the amount of money involved, particularly given the rate at which computer technology is changing. You may, in fact, be somewhat nervous, wondering if you're simply putting together a financial "black hole," requiring endless amounts of money in order to keep up with current technology. If that's true, take heart -- the PC industry (or at least part of it) is aware of this problem, and is trying to do something about it.
IBM, in particular, has been quietly at work in this regard, developing a new type of circuitry to make it easier to upgrade and update computer components. This new circuitry, known as "m-wave technology," uses a special type of component called "Digital Signal Processing" chips -- DSP for short. In essence, what this means is that, instead of using essentially permanent ROM chips to store the instructions needed to perform various tasks, a new kind of memory chip is used, which can be updated or upgraded simply by running a special program. By using this approach, such cards are essentially a "one-time" purchase, eliminating the need -- and the extra expense! -- of replacing an otherwise perfectly good card just to obtain a new feature.
Because modems and sound cards are both subject to rapid change as their respective technologies develop, it makes sense that their functions should be combined on one expansion card. In addition, voice mail capability is also frequently included, and for much the same reason. Another advantage is the savings that can be obtained by buying one card instead of two or three. This is especially true in light of the software upgrading capability mentioned above.
Again, because this technology is so new -- less than two years old at the time I write this -- there are only a few of these "DSP cards" -- currently available. Naturally, this means that the per-unit cost is somewhat high -- about $200 at this writing. This cost should come down, however, as more of these cards come on the market, making them an even better buy. In spite of this initially high cost, in our example system we will use one of these DSP units, combining sound, modem, fax, and voice mail capabilities in one card. The upgradeability feature alone, in my opinion, more than justifies the cost.
In our next installment, we'll discuss backup tape and disk drives. We'll also cover surge suppressors, uninterruptable power supplies, and other means of protecting your investment in computer hardware. See you then!
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