1541 Ultimate (often abbreviated ''1541U'') is a peripheral, primarily an emulated

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

and cartridge

emulator In computing, an emulator is Computer hardware, hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run sof ...

based on the

FPGA A field-programmable gate array (FPGA) is a type of configurable integrated circuit that can be repeatedly programmed after manufacturing. FPGAs are a subset of logic devices referred to as programmable logic devices (PLDs). They consist of a ...

Xilinx Xilinx, Inc. ( ) was an American technology and semiconductor company that primarily supplied programmable logic devices. The company is renowned for inventing the first commercially viable field-programmable gate array (FPGA). It also pioneered ...

XC3S250E, for the

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit computing, 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 ...

home computer Home computers were a class of microcomputers that entered the market in 1977 and became common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a s ...

. It became available in 2008. The unit is developed by Gideon Zweijtzer and is a cartridge that can emulate other cartridges such as the

Commodore REU The Commodore RAM Expansion Unit (REU) is a range of external RAM add-ons. At the time of introduction of the Commodore 128 home computer, two REUs were announced for that model; the 1700 (128 KB) and 1750 () REUs. Later, Commodore introd ...

Action Replay Action Replay is the brand name of a cheating device (such as cheat cartridges) created by Datel. The Action Replay is available for many computer and gaming systems including Commodore 64, Amiga, IBM PC, Nintendo DS, Nintendo DSi, Nintendo ...

, The Final Cartridge III, Super Snapshot V5, Retro Replay or TurboAss with Codenet-support, and an almost fully compatible (including JiffyDOS support FPGA-cloned

Commodore 1541 The Commodore 1541 (also known as the CBM 1541 and VIC-1541) is a floppy disk drive which was made by Commodore International for the Commodore 64 (C64), Commodore's most popular home computer. The best-known floppy disk drive for the C64, the ...

(including 1541, 1541C, and 1541 II models) floppy disk unit that can use Commodore 64-compatible files like .D64/.G64 disc images or .PRG files via a

SD card Secure Digital (SD) is a proprietary, non-volatile, flash memory card format developed by the SD Association (SDA). Owing to their compact size, SD cards have been widely adopted in a variety of portable consumer electronics, including dig ...

reader. Additionally, the 1541 Ultimate is suitable for making archives of floppy disks. All units after the initial production have 32

megabyte The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes ...

s of

RAM Ram, ram, or RAM most commonly refers to: * A male sheep * Random-access memory, computer memory * Ram Trucks, US, since 2009 ** List of vehicles named Dodge Ram, trucks and vans ** Ram Pickup, produced by Ram Trucks Ram, ram, or RAM may also ref ...

, while the original production run only had 16 megabytes. The 1541 Ultimate is capable of running both

CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Dig ...

and GEOS. In 2010, the 1541 Ultimate II was developed. The Ultimate II is about 30% smaller than the 1541 Ultimate, comes in a plastic case, and adds support for dual SIDs (plus a SID/MOD player), a

USB Universal Serial Bus (USB) is an industry standard, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

host controller, tape emulation via a tape adapter (though use with a Commodore 128D requires modification), a real-time clock (for accurate file date and time), and the SD card slot is replaced by a

microSD Secure Digital (SD) is a proprietary hardware, proprietary, non-volatile memory, non-volatile, flash memory card format developed by the SD Association (SDA). Owing to their compact size, SD cards have been widely adopted in a variety of port ...

card slot. In addition, all firmware and

VHDL VHDL (Very High Speed Integrated Circuit Program, VHSIC Hardware Description Language) is a hardware description language that can model the behavior and structure of Digital electronics, digital systems at multiple levels of abstraction, ran ...

code for the Ultimate II is available under an

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

GPLv3 The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

license A license (American English) or licence (Commonwealth English) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another part ...

, allowing hobbyists and others to freely modify all aspects of its functionality, including the FPGA-emulated hardware. The 1541 Ultimate has an option for on-board

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

, while the 1541 Ultimate II supports Ethernet via a compatible

to Ethernet adapter. Besides being useful to retrocomputing hobbyists, it has also found use in educational laboratory settings. In 2017 the Ultimate II+ was released with the following feature differentiation from the II: Removal of the MicroSD slot, More USB ports, Integrated Ethernet, Dual Flash, Integrated Speaker, External power supply connector with auto-switch over circuit, Improved power supply circuits, and a slightly bigger and faster FPGA, as to control the new features. The II and II+ share a firmware image and the software features are substantially similar.

References

External links

ultimate64.com - 1541 Ultimate homepage

1541 Ultimate source code repository
{{Webarchive, url=https://web.archive.org/web/20091013024650/http://svn.xp-dev.com/svn/gideonz_1541Ultimate/ , date=2009-10-13 (

Subversion Subversion () refers to a process by which the values and principles of a system in place are contradicted or reversed in an attempt to sabotage the established social order and its structures of Power (philosophy), power, authority, tradition, h ...

)
Collection of official and unofficial firmware
Commodore 64 Home computer peripherals

See also

References

External links