The Catweasel is a family of enhanced

floppy-disk controller A floppy-disk controller (FDC) has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof. An FDC directs and controls reading from and writing to ...

s from German company

Individual Computers Individual Computers is a German computer hardware company specializing in retrocomputing accessories for the Commodore 64, Amiga, and PC platforms. Individual Computers produced the C-One reconfigurable computer in 2003. The company is owned and ...

. These controllers are designed to allow more recent computers, such as PCs, to access a wide variety of older or non-native

disk format Disk or disc may refer to: * Disk (mathematics), a geometric shape * Disk storage Music * Disc (band), an American experimental music band * ''Disk'' (album), a 1995 EP by Moby Other uses * Disk (functional analysis), a subset of a vector space ...

s using standard floppy drives.

Principle

The floppy controller chip used in IBM PCs and compatibles was the

NEC is a Japanese multinational corporation, multinational information technology and electronics corporation, headquartered in Minato, Tokyo. The company was known as the Nippon Electric Company, Limited, before rebranding in 1983 as NEC. It prov ...

765A. As technology progressed, descendants of these machines used what were essentially extensions to this chip. Many other computers, particularly ones from

Commodore Commodore may refer to: Ranks * Commodore (rank), a naval rank ** Commodore (Royal Navy), in the United Kingdom ** Commodore (United States) ** Commodore (Canada) ** Commodore (Finland) ** Commodore (Germany) or ''Kommodore'' * Air commodore, a ...

and early ones from

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...

, 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:

Versions

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 The Commodore Amiga 4000, or A4000, is the successor of the A2000 and A3000 computers. There are two models: the A4000/040 released in October 1992 with a Motorola 68040 CPU, and the A4000/030 released in April 1993 with a Motorola 68EC030. T ...

, 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".

Mk1

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 The Amiga 1200, or A1200 (code-named " Channel Z"), is a personal computer in the Amiga computer family released by Commodore International, aimed at the home computer market. It was launched on October 21, 1992, at a base price of £399 in the ...

and one for the

. The Amiga 1200 version connected to the machine's

clock port The clock port is a commonly used term for the real-time clock interface of the Amiga 1200 computer. The port is a remnant of an abandoned design feature for addition of internal RAM and a clock for time keeping. However, it was later widely used a ...

; 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.

ISA

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 Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

Mk2 and Mk2 Anniversary Edition

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. The continued popularity of the Catweasel Mk2 led to a special "Anniversary Edition" of this model being released in 2006. The PCB of the Anniversary Edition received minor updates, however it retained the same form factor and functionality as the Mk2.

Z-II

The Catweasel Z-II version was an Amiga Zorro-II expansion that combined the Catweasel Mk2 controller with another Individual Computers product, the Buddha, on a single board providing floppy and IDE interfaces to the host computer.

Mk3

The Catweasel Mk3 was designed to interface with either a

PCI PCI may refer to: Business and economics * Payment card industry, businesses associated with debit, credit, and other payment cards ** Payment Card Industry Data Security Standard, a set of security requirements for credit card processors * Pro ...

slot, an

Amiga Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...

Zorro II Zorro II is the general purpose expansion bus used by the Amiga 2000 computer. The bus is mainly a buffered extension of the Motorola 68000 bus, with support for bus mastering DMA. The expansion slots use a 100-pin connector and the card form facto ...

slot or the

of an Amiga 1200. In addition to the low-level access granted to floppy drives, it has a socket for a

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness ...

SID sound chip, a port for an

Amiga 2000 The Amiga 2000, or A2000, is a personal computer released by Commodore in March 1987. It was introduced as a "big box" expandable variant of the Amiga 1000 but quickly redesigned to share most of its electronic components with the contemporary Ami ...

keyboard, and two 9-pin digital

joystick A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. A joystick, also known as the control column, is the principal cont ...

s (

Atari 2600 The Atari 2600, initially branded as the Atari Video Computer System (Atari VCS) from its release until November 1982, is a home video game console developed and produced by Atari, Inc. Released in September 1977, it popularized microprocessor- ...

de facto standard). The Mk3 was succeeded by the Mk4.

Mk4 and Mk4plus

The Catweasel Mk4 was officially announced on 18 July 2004, with a wide array of new features planned. However, due to manufacturing delays and production backlogs, the Mk4 was not released until early February 2005. This version of the Catweasel makes heavy use of reconfigurable logic in the form of an

Altera Altera Corporation was a manufacturer of programmable logic devices (PLDs) headquartered in San Jose, California. It was founded in 1983 and acquired by Intel in 2015. The main product lines from Altera were the flagship Stratix series, mid-rang ...

ACEX EP1K30TC144-3N

FPGA A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term '' field-programmable''. The FPGA configuration is generally specified using a hardware de ...

chip, as well as an

AMD Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactur ...

MACH110 PLD and a PCI interface IC. The Mk4/Mk4+ driver uploads the FPGA microcode on start, which makes easy updates possible without having to replace hardware. Official software and drivers are available for

, and unofficial drivers and utilities are available for

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

. The Catweasel Mk4Plus appears to be no longer available.

References

External links

Official wiki
* ttp://www.acid64.com ACID 64 Player - C64 Music Player for all HardSID cards and the Catweasel MK seriesbr>Karsten Scheibler's Linux kernel driver and command-line utilityMichael Krause's Linux block-device kernel driverArjuna floppy controller software homepageDrawBridge aka Arduino Amiga Floppy Disk Reader and WriterGreaseweazle USB Floppy Drive ReaderFluxengine USB Floppy Disk InterfaceAmigaOS & MorphOS driver development page
{{Amiga hardware Floppy disk drives Amiga MorphOS