Is it safe yet to upgrade to the new MS-DOS 6.0?


August 30, 1993|By MICHAEL J. HIMOWITZ | MICHAEL J. HIMOWITZ,(Michael J. Himowitz is a columnist for The Baltimore Sun.)

Ever since problems with Microsoft's MS-DOS 6.0 started cropping up in the spring, I've had a stream of letters and calls from users who wonder whether it's "safe" yet to upgrade to the latest version of the operating system.

Microsoft has issued a safer version of the disk-caching software that appears to be responsible for many of the data-corruption problems users have reported. But I'd still recommend waiting another month or two till the company releases DOS 6.2, which reportedly deals with most of the issues that aggrieved users have raised.

The most recent fix involves SmartDrive, a memory-resident program that improves disk performance by keeping a healthy chunk of data from your drive in a memory "cache" to make disk reads faster and delays writing data to your disk until your microprocessor isn't busy.

Delayed write caching can be dangerous because it makes your software think that data (such as a word processing document or spreadsheet) have been saved to disk when they may be held in memory for up to five seconds.

If your program hangs up during that critical period, or you turn your computer off, thinking that everything is OK, you may be in for a rude awakening next time you turn your machine on and find files or directories scrambled.

I think that's what happened to me last week, when one of my three hard drives suddenly gave me a disk directory that looked as if it had been written in Sanskrit. It was a total surprise because I had not used the DoubleSpace program (another suspect feature of DOS 6) to compress the data on that drive, and I thought I had been careful not to turn the computer off until well after I had exited from the last program I ran.

I was lucky, though. First, the drive was one I use for files I don't access very often. Second, when I bought my DOS 6 upgrade, I paid an extra $50 for a package that included the magical Norton Disk Doctor -- maybe Microsoft knew something even then.

The Disk Doctor straightened out most of the directories, but even Norton's voodoo couldn't restore a hundred or so files that had been corrupted. Luckily, I had made tape backup of the drive, and I was able to restore all but a few files.

I subsequently logged onto the Compuserve Information Service, where Microsoft has posted SmartDrive 4.2. This update has a couple of safety features. The most important is that it won't return the DOS prompt until all the data in the write cache have been stored safely on disk. It also makes it relatively easy to disable write-caching entirely. This slows disk performance, but I figure that waiting an extra second or two is better than spending half a day reconstructing a trashed hard drive.

Frequent tape backups

I'm also making frequent tape backups. If you have a large hard drive with data that you can't afford to lose, get a tape backup unit and use it regularly. Do it now, no matter what DOS version you're using.

The full DOS 6.2 upgrade is likely to take care of other problems, including those that can lead to corrupted data when you're using DoubleSpace to increase your disk capacity. If you already have a compressed disk under DOS 6 and can't wait for the upgrade, you can spend $50 for a so-called "competitive upgrade" to Stacker 3.1 for DOS and Windows.

* Interesting Question: A reader asks, "Why do those numbers tick off on my screen every time I turn on the computer? Is there any way to turn that off?"

Answer: The numbers flash by to let you know that your computer is checking its memory chips to make sure they store data accurately.

This is a safety feature that IBM built into its original PCs. A conservative company accustomed to dealing with large mainframe computers running critical programs for large businesses, IBM decided it was better to take a few seconds at the start of a session to check out the hardware than to have the computer crash because of a bad memory chip.

The first IBM PCs, outrageously slow by today's standards, went through the process without flashing anything on the screen. During the minute or two it took to make the check ,many users mistakenly deduced that there was something wrong with the computer because nothing appeared on the screen. So later models of IBM computers and clones have flashed numbers to let users know that the machine was actually doing something.

Bypass the memory check

Memory chips are much more reliable today, and a bad one is a rarity. Moreover, most machines are so fast that the checkup delay is hardly noticeable (my machine checks out eight megabytes of memory in about 10 seconds). But for impatient folks, many computers will bypass the memory check if you hit the ESC key when the numbers start to click off.

If you do have a bad chip, you'll most likely see a message that says "Parity Error." Take the computer to a repair shop where technicians can do the job quickly and painlessly.

* Sing-along Update: A few weeks ago, I reviewed a program called PC Karaoke from Sirius Publishing, which turns your computer into a Karaoke machine. I thought the program was clever and fun, but my kids just got back from camp, and they went absolutely nuts over it.

Even my wife, who takes a dim view of having fun with a computer, got into the sing-along.

Ike, who is 13, quickly figured out how to patch miniature phone jacks into RCA plugs and whatnot, the result being that it was soon possible to record the results of the Karaoke session directly onto tape. He duly recorded my rendition of "I Can't Help Falling In Love." I do not sound as much like Elvis as I thought. Programs like this should have warning labels: While singing along is fun, listening to yourself afterward can be terminally embarrassing.

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