Recently I needed a bootable medium to test a hard drive on a newer PC. I was appalled to find the old friends Hiren’s and UBCD4Win no longer in development, and much more appalled to find no clear replacement. Seagate’s SeaTools for DOS was tried first, but FreeDOS won’t support the controller. This worked well:
I booted it (its basis is 64-bit Ubuntu), opened Disks, found the test suite by clicking the round icon at the upper-right corner, and it appears to have the same functionality as SeaTools.