FDD Integrity Test Tool

Hi,

I have a 20 year old Gateway desktop PC (has WinXP).

Recently I experienced an odd issue using the
FDD (original with PC). Unlike problems I had encountered
in the past, such as Read Errors or Can't Access A: due to
a defective FDD in other PCs, there were NO error messages,
but a NEW FD I wrote files to did NOT "show up" in the A: directory!

I checked (Format A: /U) this FD in another PC and there were
NO bad sectors.

I replaced this 20 year old FDD with a spare. Everything is AOK
now.

Is there a FDD "integrity" test tool?

Thank You in advance, John