An mdb file extension is related to the ZX Spectrum emulation disk image format of MB-02 disk drive.
MDB file extension - ZX Spectrum emulator MB-02 disk format
What is mdb file? How to open mdb files?
File type specification:
The MDB file extension is associated with disk file format used to store floppy images from MB-02 disk drive designated for computers compatible with ZX Spectrum 16k, 48k, +, Delta, Didaktik Gama, 128k, +2, +2A, +3.
This mdb file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.