🚀 go-pugleaf

On Sun, 19 May 91 14:53:23 EDT Jean-Serge Gagnon said:
>I am looking for a way to hardware write protect a hard disk. I do not
>have any specific machine in mind or any particular disk in mind. At the
>University we have a concern for this and would like to be able, when it
>is asked to add some sort of switch that would prevent writing on the
>hard disk in much the same way as the write protect notch on a floppy.

OK.. I'll bite.  If you don't have a specific machine in mind, how are we
out here on the network supposed to provide specific advice?  After all,
the details on how to do this are going to differ between a Mac disk and
and an IBM PS/2 and a NeXT and so on..

The generic solution is to purchase the wiring schematics for your particular
combination of hard disk and disk controller, find the circuit that supplies
write voltage to the head assembly, and either cut it permanently or install
a switch.  Make sure to make it a debounced switch, as having transients
applied to the head while it's passing over vital data could be bad news.. ;)


                                  Valdis Kletnieks
                                  Computer Systems Engineer
                                  Virginia Polytechnic Institute