Contents of the HARDOFF.DOC file
Deactivate a Hard Disk
Program Name: HARDOFF.COM
Purpose: Temporarily turns off access to the hard drive.
Caveat: This routine makes use of IBM BIOS Interupts, it may
not be compatible on some clones. I have been using
this routine on an IBM-XT with a 20 Meg Seagate drive.
Operation: Executing HARDOFF.COM will perform two tasks:
1. HARDON.COM will be created.
2. Read/Write Access to the hard drive will be
After execution, any attempt to Read/Write the
hard drive will result in the error message:
General Failure Error
Reading Drive C:
Abort, Retry, Ignore?
To reactivate the hard drive, execute HARDON.COM.
After reactivating the hard drive controller, HARDON.COM
will suicide by deleting itself.
Since most systems maintain COMMAND.COM on the hard drive,
I recommend that you create the following batch file,
appropriately modified for your system, to actually use
COPY C:\COMMAND.COM D:\
COPY C:\HARDOFF.COM D:\
This is necessary as DOS will attempt to reload COMMAND.COM
when you execute HARDON.COM, since COMMAND.COM resides on
the hard drive, and it has been locked out, a general
DOS system failure will occur and it will be necessary to
boot the system.
Of course, before you run the batch file, make sure the
program and any necessary files you are checking out
are residing on Drive D:. On my system this is a
RAM disk but it could just as easily be Drive A:.