NationMaster - Encyclopedia: Commodore 1581

The Commodore 1581 is a 3½ inch double sided double density floppy disk drive made primarily for the Commodore 64 and Commodore 128 home/personal computers. The drive stores 800 kilobytes using an MFM format different from both DOS (720 KB), and the Amiga (880 KB) formats. It was released in the summer of 1987 and quickly became popular with Bulletin board system operators and other users. Double Density usually refers to a physical format in a magnetic storage system that uses twice as many bits per length unit as the basic format. ... A floppy disk is a data storage device that is composed of a circular piece of thin, flexible (i. ... The Commodore 64 (C64, CBM 64) was a popular home computer of the 1980s. ... The Commodore 128 is a home/personal computer, also known as the C128. ... The home computer is a consumer-friendly word for the second generation of microcomputers (the technical term that was previously used), entering the market in 1977 and becoming common during the 1980s. ... A kilobyte (derived from the SI prefix kilo-) is a unit of information or computer storage equal to either 1024 or 1000 bytes. ... Modified Frequency Modulation, commonly MFM, is the magnetic data recording scheme used by most floppy disk formats, notably by most CP/M machines, as well as PCs running DOS. MFM is a modification to the original FM (frequency modulation) scheme for encoding data on single-density floppy disks. ... The acronym DOS stands for disk operating system, an operating system component for computers that provides the abstraction of a file system resident on hard disk or floppy disk secondary storage. ... In computing, Amiga is a range of home/personal computers primarily using the Motorola 68000 processor family, whose development started in 1982, initially as a game machine. ... 1987 is a common year starting on Thursday of the Gregorian calendar. ... A bulletin board system or BBS is a computer system running software that allows users to dial into the system over a phone line and, using a terminal program, perform functions such as downloading software and data, uploading data, playing games, reading news, and exchanging messages with other users. ...

Like the 1541 and 1571, the 1581 has an onboard MOS Technology 6502 CPU with its own ROM and RAM, and uses a serial version of the IEEE-488 interface. Inexplicably, the drive's ROM contains commands for parallel use, although no parallel interface was available. Like the 1571, it can read various other disk formats using special software. This capability was most frequently used to read MS-DOS disks. However, unlike the 1571, which is nearly 100% backward-compatible with the 1541, the 1581 has limited compatibility with Commodore's earlier drives. Although it responds to the same DOS commands, most disk utilities written prior to 1987, most notably fast loaders, are 1541-specific. The Commodore 1541 (originally called VIC-1541), made by Commodore Intl, was the best-known floppy disk drive for the Commodore 64 home computer. ... The Commodore 1571 was arguably Commodores finest 5¼ floppy disk drive, having the ability to use double-sided disks without the need to remove them and turn them over (flippy disk) as in the previous Commodore drives on which it was based (Commodore 1541, 1570). ... The MOS Technology 6502 is an 8-bit microprocessor designed by MOS Technology in 1975. ... The Hewlett-Packard Instrument Bus (HP-IB), is a short-range digital communications cable standard developed by Hewlett-Packard (HP) in the 1970s for connecting electronic test and measurement devices (e. ...

The 1581 added support for partitions, but this was largely unused. It implements faster burst mode access than the Commodore 1571 5¼" drive. The 1581 provides a total of 3160 blocks free when formatted (a block being equal to 256 bytes). The number of permitted directory entries was also increased, to 288 entries. It is the highest capacity serial bus drive ever made by Commodore ('double-check: Commodore's SFD-1000 was a 1 MB drive preceding the 1581' 'triple-check: the SFD-1001 was the 1MB drive, running on an IEEE-488 interface'), and the only 3½" one. However, starting in 1991, Creative Micro Designs (CMD) made the FD2000 high density (1.6MB) and FD4000 extended density (3.2MB) 3½" disk drives, both of which offered not only a 1581 emulation mode but also 1541 and 1571 modes. In July 2001, production and sale of the FD2000 was taken over by Click Here Software Co. burst mode in computing In a computing environment, burst mode refers generically to any situation in which a device is transmitting data repeatedly without waiting for input from another device or waiting for an internal process to terminate before continuing the transfer of data. ... The Commodore 1571 was arguably Commodores finest 5¼ floppy disk drive, having the ability to use double-sided disks without the need to remove them and turn them over (flippy disk) as in the previous Commodore drives on which it was based (Commodore 1541, 1570). ... This article refers to the unit of binary information. ... Commodore is the commonly used name for Commodore International, a West Chester, Pennsylvania based electronics company who was a major player in the 1980s home computer field. ... Creative Micro Designs (CMD) is a computer technologies company which today sells x86 PCs and equipment, but which started out in 1987 selling self-designed hardware for the Commodore 64 and C128 8-bit computers. ...

Utilities to read 1581-formatted disks in standard PC floppy drives under Linux or Microsoft Windows exist. Tux, a cartoon penguin frequently featured sitting, is the official Linux mascot. ... // Microsoft Windows is a range of operating environments for personal computers and servers. ...

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