Individual Computers Catweasel

The Catweasel is a family of enhanced floppy-disk controllers from German company Individual Computers. These controllers are designed to allow more recent computers, such as PCs, to access a wide variety of older or non-native disk formats using standard floppy drives.

The floppy controller chip used in IBM PCs and compatibles was the NEC 765A. As technology progressed, descendants of these machines used what were essentially extensions to this chip. Many other computers, particularly ones from Commodore and early ones from Apple, write disks in formats which cannot be encoded or decoded by the 765A, even though the drive mechanisms are more or less identical to ones used on PCs. The Catweasel was therefore created to emulate the hardware necessary to produce these other low-level formats.

The Catweasel provides a custom floppy drive interface in addition to any other floppy interfaces the computer is already equipped with. Industry standard floppy drives can be attached to the Catweasel, allowing the host computer to read many standard and custom formats by means of custom software drivers.

Supported formats:

The initial version of the Catweasel was introduced in 1996 and has since undergone several revisions. The Catweasel Mk1 and Mk2, for the Commodore Amiga 1200 and Amiga 4000, sold out in October 2001. The Mk3 added PCI compatibility and sold out in mid-2004. It was succeeded by the Mk4. The Mk2 was re-released in 2006 as a special "Anniversary Edition".

The original version of the Catweasel was introduced in 1996 for the Amiga computer, and was available in two versions - one for the Amiga 1200 and one for the Amiga 4000. The Amiga 1200 version connected to the machine's clock port; the Amiga 4000 version connected to the machine's IDE port. A pass-through was provided on the Amiga 4000 version so that the IDE port could still be used for mass storage devices.

A version of the Catweasel controller was developed for use in a standard PC ISA slot as a means of reading custom non-PC floppy formats from MS-DOS. Custom DOS commands are required to use the interface. Official software and drivers are also available for Windows.

The Mk2 Catweasel was a redesign of the original Catweasel, merging the Amiga 1200 and Amiga 4000 versions into a single product that could be used on both computers, and providing a new PCB layout that allowed it to be more easily installed in a standard Amiga 1200 case.