Toshiba HX-F101 external floppy disk drive problem.

It would be very interesting to study the original disk ROM of this Toshiba HX-F101, for example in order to get it emulated.

As msxholder said, most interesting part is how it is controlling the FDC. That's where it differs (which memory addresses, mirrors, or even I/O ports). The FDC's themselves, which are used on MSX, are mostly WD2793 or compatibles.

When you write that the FDD has no activity are you talking about the original drive or the PC one?
Did you do any mod to the PC one to adapt it to MSX?

@Hokuspokus perhaps if you upload the ROM dump you took, others can have a look at it. This may also perhaps reveal why you cannot flash it back.

You don't. You find some other place to upload it, and provide a link.

Some people just use a google drive link, but anywhere will do that you can easily link to.

Alas, that looks quite corrupted... can you try again?

Example:

oBooeoerror
re s ana k y f f rrtry-y$

should be:

Boot error
Press any key for retry