It's hard to believe that computer users will put up $30 or $40 for a program that does absolutely nothing, but After Dark, from Berkeley Systems, does nothing with such elan that the price seems almost a pittance.
After Dark is a screen blanker, or more accurately a screen saver. It takes over when your PC is idle for more than a few minutes, replacing whatever appears on your monitor with a dazzling aquarium, a screenful of flying toasters, or one of dozens of other animated images.
When you press a key or use your mouse, it restores your !B original screen and goes back to sleep.
Why bother? Actually, there are a couple of good reasons. In fact, screen blankers have been around in one form or another for many years.
They're designed to eliminate a problem called "burn-in," which can occur when you leave the same image displayed on your computer screen for hours at a time.
On some monitors, the phosphors that make the screen light up have memories. Leave them lighted long enough, in the same pattern, and you can permanently etch the image onto your screen. At best, the problem is annoying. At worst, it can render your monitor virtually useless and require replacement of the cathode ray tube.
Screen blankers are programs that lurk in the background, monitoring system activity. If your PC runs for more than a set amount of time without a keystroke or mouse click, the screen blanker saves the current screen and then either turns off the display or replaces it with a constantly changing graphic image.
Besides saving your monitor, a screen blanker is a useful security tool. If you get called away from your PC suddenly and have to stay away for a while, it's nice to know that whatever you've been working on won't be displayed to the world in your absence.
Programmers have been writing screen blankers since the dawn of the PC. Many are available free, or for a nominal charge, from computer bulletin boards, user group libraries, and on-line information services such as Compuserve or Genie.
After Dark, available for Apple Macintosh computers and IBM compatibles running Microsoft Windows, is a commercial RTC program that virtually redefines the genre. In the end, it may do nothing more than other screen blankers, but it's so elegant and fun to fool with that it's worth the price ($49.95 list, $30 to $40 on the street).
The new IBM version, which I reviewed, requires the Microsoft Windows graphical operating environment. A separate program in the package will black out your screen while you're running in standard DOS mode, but you can find DOS programs to do that a lot cheaper.
When you invoke After Dark, it presents you with a menu of 36 different animations. You can choose the display you want, tell the program how long to wait before it takes over, and forget it.
Or, you can have some fun with it. In fact, it's easy to blow away an hour or so just finding out what the program will do.
Each animation is customizable, and a demonstration mode lets you preview the results of your handiwork. For example, you can tell the program how many fish to put in the aquarium display, or how many toasters you want flying across your screen, or even tell it how well done you want the toast.
You can fill your screen with bouncing balls (of different sizes), impressive but meaningless graphs of your choosing, pictures of mountains or geometric kaleidoscopes. You can make your existing screen literally wash down a drain or display a rotating globe.
If you don't like the images After Dark provides, you can roll your own. You can make a scanned company logo float across the screen or use any small graphic saved in Windows' bitmap format. There's even a slide show feature that will take an entire ++ directory full of images and display them in sequence.
If simplicity is your thing, just type a message, such as "Out to lunch" or "Touch this computer and you're dead meat" and have After Dark float it across the screen.
For security purposes, you can attach a password to After Dark that will keep the curious out and allow only you to restore the original screen. For users on networks, there's a separate program that sets up a master password allowing system administrators to override individual passwords.
The instruction manual is brief and occasionally confusing, but After Dark is so easy to use that you probably won't have to refer to it much. There's an excellent section at the end for programmers who want to develop their own animations, and Berkeley Systems is actively seeking animated art for future releases and updates.
Like most background programs, After Dark does use some computing resources. The program has a "System IQ" activity monitor that checks to see how hard your computer is working. For example, it might be transferring large files to another computer via a modem, or sorting a large data base, when After Dark takes over.
If your computer is working too hard, After Dark will slow down its animation or stop entirely until activity returns to normal.
Also, if you're doing something that requires a lot of system horsepower, such as printing a large graphic, you may want to turn After Dark off entirely to improve performance.
While $30 or $40 might seem a bit steep for a program like this, After Dark is a good value for the money. It's entertaining; it performs a useful function and it works.
After Dark, with a list price of $49.95, is a background program that prevents monitor "burn-in" by displaying dazzling animations on the screen of an idle computer.
Requirements: An Apple Macintosh or an IBM-compatible running Microsoft Windows.
Publisher: Berkeley Systems, 1700 Shattuck Ave., Berkeley, Calif. 94709.