Re: You can get it back
Given the machine's age, that should be trivial. _The Peter Norton Programmer's Guide to the IBM PC_,Jun 1985, would have you write The Magic Byte* to appropriate areas of the File Allocation Table(s) (FAT. Both of them) to mark a bad sector. Use debug.com, or Norton's diskedit.exe
* Can't recall the value. It looks like an upside-down 'e' in the ASCII chart. Use the Alt key and the numeric keypad. It must be nap time by now. Where's my nurse?