FS-TST-1_0-update.zip is an update to FS-TST version 1.0 that contains revised versions (3.2) of both badx13 and baddisk. The revision fixes a problem with error simulation that occurs in version 3.1 of the tools. If version 3.1 is used to designate a disk sector for error return on access and interrupt 21 is used to access the hard drive, no error is reported after the interrupt 21 return that accessed the sector designated to report an error (the error was "lost" since interrupt 21 is a DOS not a BIOS interrupt). Interrupt 13 error return was not impacted. 