kpk@gitpyr.UUCP (Kevin P. Kleinfelter) (01/23/86)
Recently there has been discussion of copy protection schemes trashing disks. Another case where disks can get trashed is when the programmer is developing software which may alter MS-DOS memory, and possibly causing invalid directory information to be written to the disk. On a floppy based system, these disasters are easy to avoid: you just put a write protect tab on the endangered diskette, and test away (or just make a quick backup). These approaches are inappropriate for a hard-disk based system. (There is no write protect notch, and a "quick" backup can take over an hour!) You can argue that booting your hard-disk PC from a floppy means that MSDOS doesn't know about the hard disk, and therefor won't update it erroneously, but if I am writing software which mucks about with memory and IO ports, I still might end up trashing my precious 20 megs. Why doesn't anyone sell a hard disk with a write protect switch on the front bezel? What would be involved in adding one? (I assume that there must be a write enable line from the controller to the disk. Would I simply need to install a SPST toggle switch in this line, or would it be more complex?) Disclaimer of responsibility: I am irresponsible.