Classic Computer Magazine Archive COMPUTE! ISSUE 49 / JUNE 1984 / PAGE 10

Protected Disks

What exactly is the difference between write-protected and copy-protected disks? Can these protection devices be evaded on disk? Also, if my friend buys a program on disk, is there any way to transfer it to tape for me?

Jon Regen

Write-protected disks are disks that can be read from, but not written to. As you hold a disk in the normal fashion, and slip it into your disk drive, you'll notice a little square notch cut out of the left side of the protective sheath. Inside your disk drive are a light-emitting diode and a phototransistor.

These two components are in-line with each other, and when you insert a disk, the light from the LED shines through the notch and into the phototransistor. If the transistor detects the light, then the drive is allowed to write to the disk.

To write-protect a disk, place one of the sticky tabs included with the disk over the square hole. This will stop the light from reaching the phototransistor, and signal the drive not to write to this disk. An attempt to write will cause the red error light on the front of the drive to blink.

Copy protection is a different matter. More often than not, commercial software is copyrighted. This means that you may not (under penalty of law) make a copy for any purposes other than specified by the software distributor. Software manufacturers use several different methods to prevent copying, from different programming techniques to special coding on the diskette.

As for making a tape copy of the programs, the same answer applies. The copyright laws cover all copies, whether on tape or disk. Copies should not be made unless permitted by the software company.