The Catweasel MkIII is quite a unique card, but is very innovative. It can be connected in many different ways. It can be used in a PCI slot, flipped upside down and used in a Zorro slot in big box Amigas, or it can be attached to the clockport on the A1200. The main purpose of the Catweasel is to allow access to non-standard disks using ordinary PC-diskdrives, even when all other solutions require the original computer. The Catweasel is capable of reading almost any disk format in 5.25" and 3.5" drives. For example, you can read a C64 170K 5.25" disk, even in a 1.2MB PC 5.25" disk drive. Individual computers are currently working on supporting over 1100 disk formats.
Unlike the earlier versions of the Catweasel, this version also includes two SUB D-9 digital joystick ports, the exact same ports as used for mice and joysticks on the Amiga, Atari and countless other computers and consoles. Also included on the card is a mini-DIN connector, designed for connecting A4000 keyboards, or with a PS/2 adaptor you can also connect A2000 and A3000 keyboards. Last but not least, the card has a SID chip on it. The SID chip was responsible for producing the sound in the Commodore 64!. The Catweasel is also capable of activating the fourth voice on both the 6581 and 8580 versions of the SID chip.
The Catweasel Mk-III is designed to be used in both Amigas and PC's, however it is not clear whether all available features would work in both machines. For example, I don't know if it's possible to use the keyboard connector if the card is connected to an Amiga. Apparently the card can be used in PCI mode in Amiga's fitted with PCI busboards but this has not been confirmed.
Thanks to Mario Misic