A New Way to Boost Storage Capacity

In the world of personal computing there is almost always a better way to do something.

A hardware manufacturer in Santa Clara, Calif., Integrated Information Technologies, (800) 832-0770, is one of the latest companies to demonstrate that truism.

It did so with a software product, XtraDrive, that grew out of the firm’s need for a program to operate a data compression chip it had designed. IIT has been in the business of making math co-processors and video display enhancement chips.

The resulting software is a significant advance over the market leading disk compression products, Stacker and SuperStor.

XtraDrive, $99, essentially doubles the capacity of an IBM or compatible hard disk that is equipped with the DOS operating system. The computer must have an 80286 or later generation microprocessor. The extra storage space is obtained with a process called data compression, which is sort of like rewriting a computer file in shorthand.

Compared to its competitors, XtraDrive establishes a closer relationship with the computer’s hardware, allowing it to operate at something called the “BIOS level,” if you’re technically minded.

That difference is important because it makes XtraDrive more compatible with the other programs already on your computer. And it allows you to more easily change your mind later about using it.

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Both Stacker and SuperStor work by creating a single giant file on your hard disk. Your other files are stuffed into the hard disk in compressed format. They have to “trick” DOS into reaching into that single giant file to store or retrieve programs and data. That works fine as long as all of your programs let DOS handle their file access for them. Some don’t, however.

Windows running in its most efficient configuration on 386 and 486 computers bypasses DOS to use something it calls a “swap” file, so you have to make special provisions for that if you install Stacker or SuperStor. If you aren’t technically savvy about your computer, you’ll have trouble doing that.

Some routines in disk utility programs, such as Norton Utilities and PC Tools, won’t work properly under SuperStor or Stacker.

The other big objection I have to the market leaders is that installing SuperStor or Stacker is a one-way process. There is no easy way to undo what you’ve done if you don’t like the way it works.

The only way to remove them is to reformat the hard disk, which erases all the files stored there. Then you have to load your original software diskettes, or backup copies of them, onto the newly formatted disk.

I had to go through that hassle when I removed SuperStor from my computer earlier this year because it took away too much RAM memory for my normal programs to run.

XtraDrive avoids all of those problems, which makes it more suited for users who aren’t technically adept.

It stores your files separately on the hard disk. All of your programs can find those files, whether they rely on DOS to handle file access or not. That means that the Windows permanent swap file is unaffected, as is Norton Utilities and most other utility software.

You don’t even have to know what those things are or whether they exist on your computer to successfully use XtraDrive, which is the most important thing that can be said in its favor.

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If you want to get rid of XtraDrive, you can simply remove it, with a program that comes on the program disk. The only caveat is that there has to be room on your hard disk for the decompressed files to fit, or you will lose those that don’t fit. That is easily managed by copying the excess files to floppy disks before removing XtraDrive.

On my test machine, a 386/20 PC clone with a 145-megabyte hard disk, it took about 26 minutes to install and compress the 100 megabytes of files stored on the disk. Afterward I had about twice as much disk storage space.

To work this magic, XtraDrive needs to load a small program, about 40 kilobytes, into memory when the computer starts up. It did this without losing memory to run my regular programs.

With XtraDrive installed, that program has to do a fair amount of work every time you open a program. It has to decompress the program and data files and load them into memory. Then, when you save new data, it has to recompress that file back to the disk.

I really couldn’t sense any difference in my computer’s performance, despite the extra work. One reason is that the short compressed files take less time to read from or write to the disk, which helps to compensate for the processing time required to do the decompression and compression routines.

There is, in fact, a performance penalty, however, as the stopwatch proved. Before installing XtraDrive, it took 22 seconds to open Windows on my computer and another 15 seconds to open a blank AmiPro 2.0 word processing document.

With XtraDrive installed, those times jumped to 28 seconds and 22 seconds, respectively, which is a 27% penalty for opening Windows and a 47% slowdown for AmiPro.

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That could be a problem if you routinely work with very large Windows program data files, which seem to take forever to load anyway. You’ll have to balance that problem against the advantage of doubling your disk storage without buying a new hard drive.

There is a solution, which may be available by the time you read this. IIT is building a data compression circuit board to install in the computer, which will significantly speed up the compression-decompression cycle. It will be priced at $199.