Classic Computer Magazine Archive COMPUTE! ISSUE 141 / JUNE 1992 / PAGE 50

Avoid the boot-up blues. (bootable floppy disks) (Column)
by Tony Roberts

What do you do if your hard drive refuses to boot?

A. Scream. B. Take an early lunch. C. Take an early retirement. D. Pray for an early visit by a computer guru. E. Try rebooting with your back-up system floppy.

If you answered E, you're on the right track. Occasionally, something goes wrong with the hard drive's crucial boot data, and the hard drive thinks it's a nonbootable device.

A system floppy is often all it takes to get you back in operation, but I'm willing to bet you'd have trouble laying your hands on a bootable floppy in a pinch. If you do have a bootable floppy, are you sure it holds the current DOS version?

If your bootable floppy is either nonexistent or outdated, take a couple of minutes to create one now using the DOS FORMAT command. Insert a new floppy in drive A: and enter FORMAT A: /S. This operation formats the disk and copies COMMAND.COM and the hidden DOS system files to it.

With your new bootable floppy you're in good shape if trouble arises, but if you want to be even better prepared, copy SYS.COM and CHKDSK.EXE to the disk along with a small text editor and as many of your favorite disk tools as will fit.

If your hard disk ever fails to perform, boot from the floppy and see if you can access the files on the hard disk. If the hard disk is accessible, switch to the C: drive and run CHKDSK to verify that the data on the drive is intact. If CHKDSK runs clean, you can then run AUTOEXEC.BAT and go about your normal business.

Making repairs is usually relatively easy, but the approach depends on the reason for the failure. If COMMAND.COM on drive C: is missing or mangled, simply copy a fresh version from your floppy disk. Be certain that the DOS versions on your hard and floppy disks are the same; COMMAND.COM doesn't work very well in mix-and-match mode.

Similarly, DOS's hidden files, if damaged, could prevent boot-up. To copy new versions of these files to your hard disk, use the SYS C: command after booting with your floppy.

Another possible reason for failure is that something in your CONFIG.SYS file causes the system to hang before it ever gives you control. If you've added a new driver or recently edited CONFIG.SYS, consider this possibility.

One way to isolate such a problem is to rebuild CONFIG.SYS a line at a time until you see what causes the system to stumble. In one odd case I worked on, I finally discovered that the system hung up during the load of the ANSI.SYS device driver. I couln't figure out why such a ubiquitous device driver would cause a problem until I noticed that the ANSI.SYS file was half its normal length. Once I replaced it with a whole copy from the DOS disks, the problem was solved.

A less easily explainable problem occurs when the hard disk's boot sector suddenly goes bad. Although rare, this problem has bothered me on a few occasions. Each time I thought that an entire hard disk reformat was in the offing, but I always found an easier solution using one of the disk-repair utilities, such as Norton's Disk Doctor or PC Tools Diskfix.

The important thins is to be prepared so you can recover from trouble and be back at work with as little difficulty as possible.

An added benefit to a bootable disk loaded with all of your favorite utilities is that it comes in handy when you need to use someone else's computer temporarily. Working on an unfamiliar system can be much friendlier if you have access to at least a few of your usual tools. So format that bootable floppy and stash it where you can always find it.

Speaking of formatting disks, those of you with MS-DOS 5.0 installed should check out the new punch that this version of FORMAT carries.

The nicest addition to the program, by my way of thinking, is the ease with which you can tell DOS which size disk you're formatting. If you're trying to format a 720K disk in a 1.44MB drive, you can forget the cryptic /T:80 /N:9 string you used to use to pass along information about tracks and sectors on the target disk.

FORMAT now takes a /F switch with which you simply specify the size of the disk you're formatting. FORMAT B:/F:720, for example, is all it takes to format that 720K floppy in a high-density drive.

Another nice feature is that FORMAT uses the MIRROR command to save a copy of the target floppy's file allocation table. This makes unformatting possible if you suddenly realize that you had the wrong disk in the drive when you pressed the Enter key.

Also in the DOS 5.0 version of FORMAT is the quick format--the /Q switch. This option lets you reformat previously formatted media in seconds. Although this is a great timesaver, you should use this method only when working with disks that you know are good. The quick format is quick because all it does is create a new file allocation table and root directory; it doesn't scan for bad sectors.