Can't quite tell from the photo, but the external floppy connector looks like a 25 pin dsub, which I think is the same as the T5200, which there was a thread about elsewhere, in which Shimart designed a small board to convert from the 25 pin to a standard PC 34 pin floppy connector:
Re: Toshiba T5200 mods and upgrades

It wouldn't be too hard to make up a cable to do the same sort of thing.

Interesting thing is how it gets the Ready signal (not present on the PC floppy connector) by using the MotorOn signal to immediately signal Ready.

There's a pinout of the 5200 port in the service manual here (page 166): http://www.minuszerodegrees.net/manuals/Toshi … ce%20Manual.pdf
Can't just find a service manual for the 225, so there's a chance Toshiba changed the pinout between the models, but that seems unlikely.

That laptop needs the PA2611U external floppy drive case - here's what mine looks like, but they come in both light grey and dark grey versions with the same part code. You might also just have more luck searching for "toshiba (floppy,fdd,floopy)" to find all Toshiba floppy drives, since not everyone includes the part code in their description when selling it.
Beware though, there are other versions of the external floppy case that have a different connector - make sure to get the external caddy with this shape and the 'pinch to eject' design. The long rectangular one with the button on the back will not fit your laptop.

I don't know what the part code for the floppy drive that goes into the caddy is, mine has no stickers. But I do know it's a Teac or Mitsumi floppy drive - which are both direct drive, so no belts to fail and they're much more likely to just work.

You can get a floppy drive for any of these models and they're interchangeable into your laptop's media bay - just unclip the shell and put your CD drive's media bay shell on it, then install it in place of the CD drive:
Toshiba Satellite 220, 230, 440, 460, 470,480,490 laptops
Toshiba Tecra 520, 530, 540, 550, 8000, 8100, 8200 laptops