There's no such thing as a free lunch. Or is there?
Consider Stacker, a utility for IBM-compatible computers that claims it "doubles your disk capacity."
My opinion of the claim has always been, basically, "Yeah, right!" While I never doubted that Stacker or any other compression utility could compress a hard drive, I felt pretty certain that, when you tried to actually use the disk, you'd waste a good deal of time waiting while programs and files were decompressed and compressed.
But events have conspired to change my opinion.
First, a couple of months ago, the 210-megabyte hard drive on the computer that runs my bulletin board filled up. I performed some long-needed disk maintenance and freed up 40MB or so of space, then I began looking to buy an additional drive.
Unfortunately, there were no drives to be found. To add a second IDE drive to a PC, you need to ensure that the new drive exactly matches the first -- same size, brand, model and everything. There is currently, though, a hard-drive shortage, especially of 40MB, 80MB and 210MB drives.
And system manufacturers have taken a real shine to the Western Digital drive I have in that PC (because they're well made but a little cheaper than other brands) so it's especially hard to find.
Meanwhile, I bought a notebook computer, which came with the newest version of Stacker. Holding the opinion I did, I had no intention of using it.
Then, the bulletin board drive again filled up. There were no more unnecessary files to kill, so I had the option of either deleting some of the software available for download, or giving Stacker a try.
I opted for Stacker. And it works as advertised.
Or almost. Because all the files in the bulletin board's software-exchange area are already compressed by a shareware program called PKZip, I didn't get a doubling of my disk space.
But I did get nearly 100 free megabytes from the full 210MB drive. And files that weren't already compressed were compressed at least 2-to-1 by Stacker, some even 5-to-1.
How it works is like this: On a drive that's already filled with data, Stacker compresses almost everything on the drive into a single file. It then tells DOS that this file is your old C: hard drive.
It also fools DOS into thinking that you have another hard drive. Onto this new hard drive (D: on my setup), it copies DOS and all the other files your PC loads when it starts up. Nothing on this drive is compressed.
Now, the uncompressed D: drive is really your old C: drive, so when your computer reboots, it loads all the uncompressed startup programs just as normal.
As soon as Stacker loads automatically, it tells DOS to call the C: drive D: and to recognize its compressed collection of files as your C: drive.
When DOS calls for one of the C: drive files, Stacker automatically and nearly instantly decompresses the file back into its normal form. Once DOS finishes with the file, Stacker automatically compresses it again.
All this compression is done very quickly. When calling up a file from the DOS prompt, I can barely tell that it takes longer to load than normal.