CatWeasel - AbsoluteAstronomy.com

The Catweasel is a family of enhanced floppy disk controller

Floppy disk controller

A floppy disk controller is a special-purpose chip and associated disk controller circuitry that directs and controls reading from and writing to a computer's floppy disk drive . This article contains concepts common to FDCs based on the NEC µPD765 and Intel 8072A or 82072A and their descendants,...

s from German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

company Individual Computers

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...

. These controllers are designed to allow more recent computers, such as PC

IBM PC compatible

IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...

s, to access a wide variety of older disk formats using standard floppy drives.

Principle

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

NEC

, a Japanese multinational IT company, has its headquarters in Minato, Tokyo, Japan. NEC, part of the Sumitomo Group, provides information technology and network solutions to business enterprises, communications services providers and government....

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

Commodore International

Commodore is the commonly used name for Commodore Business Machines , the U.S.-based home computer manufacturer and electronics manufacturer headquartered in West Chester, Pennsylvania, which also housed Commodore's corporate parent company, Commodore International Limited...

and early ones from Apple

Apple Computer

Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

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 normally sits between the computer's floppy interface and the floppy drives, modifying the signals as they pass. This allows one to mount PC floppies and then read or write, say, Amiga floppies without needing separate drives. The card may also be operated alone with no assistance. Foreign formats may be read and written in a setup like this, but regular PC floppies cannot be mounted. The hardware does support mounting disks, but the drivers currently do not. In any case, a Catweasel cannot be used to boot a computer unless it is assisted by a regular PC floppy interface.

The ability to read and write media on modern computers for older ones is a crucial element of getting the most out of retrocomputing

Retrocomputing

Retrocomputing is the use of early computer hardware and software today. Retrocomputing is usually classed as a hobby and recreation rather than a practical application of technology; enthusiasts often collect rare and valuable hardware and software for sentimental reasons...

. The Catweasel, therefore, is a very valuable tool for preserving data as well as getting new data into the old computers.

Supported formats:

System	Floppy	Size
Amiga	3.5"	880, 1760 KB
Apple Macintosh	3.5"	400, 800, 720, 1440 KB
MS DOS	3.5"	720, 1440 KB
MS DOS	5.25"	360, 720, 800, 1200 KB
Atari ST	3.5"	360, 720, 800, 1440 KB
Atari 800 XL	5.25"	130, 180 KB
Apple II	5.25"	140 KB
Commodore 1541	5.25"	170 KB
Commodore 1571	5.25"	170, 341 KB
Commodore 1581	3.5"	800 KB
Catweasel Extra	3.5"	1160, 2380 kB
Nintendo backup station	3.5"	1600 KB

Mk1 and Mk2

The initial version of the Catweasel was introduced circa 1996 and has since undergone several revisions. The Catweasel MK1 for the PC ISA bus and Catweasel MK2, for the Commodore Amiga 1200

Amiga 1200

The Amiga 1200, or A1200 , was Commodore International's third-generation Amiga computer, aimed at the home market...

and Amiga 4000

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....

, sold out in October 2001. The MK3 added PCI compatibility, sold more units than the MK2, and sold out in mid-2004. It was succeeded by the MK4.

MK3

The Catweasel MK3 was designed with the goal of maximum compatibility, and would interface with either a PCI

Peripheral Component Interconnect

Conventional PCI is a computer bus for attaching hardware devices in a computer...

slot, an Amiga

Amiga

The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...

Zorro II

Zorro II is the name of 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 factor is the same as the IBM PC...

slot or the clock port

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 as a general purpose expansion port by third-party...

of an Amiga 1200. In addition to the low-level access granted to floppy drives, it has a socket for a Commodore 64

Commodore 64

The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...

SID

MOS Technology SID

The MOS Technology 6581/8580 SID is the built-in Programmable Sound Generator chip of Commodore's CBM-II, Commodore 64, Commodore 128 and Commodore MAX Machine home computers...

sound chip, a port for an Amiga 2000

Amiga 2000

The Amiga 2000, or A2000, is a personal computer released by Commodore in 1986. It is the successor to the Amiga 1000.-Features:Aimed at the high-end market, the original Europe-only model adds a Zorro II backplane, implemented in programmable logic, to the custom Amiga chipset used in the Amiga 1000...

keyboard, and two 9-pin digital joystick

Joystick

A joystick 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. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...

s (Atari 2600

Atari 2600

The Atari 2600 is a video game console released in October 1977 by Atari, Inc. It is credited with popularizing the use of microprocessor-based hardware and cartridges containing game code, instead of having non-microprocessor dedicated hardware with all games built in...

de facto standard).

The SID chip socket allows Catweasel users to play SID chiptune

Chiptune

A chiptune, also known as chip music, is synthesized electronic music often produced with the sound chips of vintage computers and video game consoles, as well as with other methods such as emulation. In the early 1980s, personal computers became cheaper and more accessible than they had previously...

s on the real chip instead of relying on software emulation for original sounding SID playback. The WinVICE

VICE

The software program VICE, standing for VersatIle Commodore Emulator, is an emulator for Commodore's 8-bit computers, running on Amiga, Unix, MS-DOS, Win32, Mac OS X, OS/2, Acorn RISC OS, and BeOS host machines...

emulator supports the Catweasel's SID features starting with version 1.13.

As of September 2004, software support for major operating systems such as Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

and Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

was limited, although new drivers and hardware were under development (see below). The most promising development for the floppy controller portion was reported to be a modular software product for Windows called Arjuna

Arjuna

Arjuna in Indian mythology is the greatest warrior on earth and is one of the Pandavas, the heroes of the Hindu epic Mahābhārata. Arjuna, whose name means 'bright', 'shining', 'white' or 'silver' Arjuna (Devanagari: अर्जुन, Thai: อรชุน, Orachun, Tamil: Arjunan, Indonesian and Javanese: Harjuna,...

, the first public version of which was announced on 8 February 2004.

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.

The latest versions of the Catweasel make heavy use of reconfigurable logic in the form of FPGA

Field-programmable gate array

A field-programmable gate array is an integrated circuit designed to be configured by the customer or designer after manufacturing—hence "field-programmable"...

chips. On the MK4, software drivers may update the hardware directly so that e.g. unsupported disk formats at the time of shipping can be added simply by downloading the new setup code through the Internet and then reprogramming the hardware core with the Catweasel still sitting in the host computer.

The Catweasel MK4 has drivers for Linux

Linux

, Windows

Microsoft Windows

98SE/ME/2000/XP, and Amiga OS; additionally, the intention is to support Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

at a later date.

The Catweasel MK4 has now been discontinued, Individual Computers has stated that they plan to release an external Catweasel compatible with laptops, thus not requiring a PCI slot. They have not, at present, announced a release date for this new revision.

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.