Amiga Unix (informally known as Amix) is a discontinued full port of AT&T Unix System V Release 4 operating system developed by Commodore-Amiga, Inc. in 1990 for the Amiga computer family as an alternative to AmigaOS, which shipped by default.

This article possibly contains original research. (August 2008)

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Amiga UNIX

Amiga Unix installation disks and tape
Developer	Commodore-Amiga, Inc.
OS family	Unix (SVR4)
Working state	Historic
Source model	primarily closed source
Initial release	1990; 34 years ago (1990)[1]
Latest release	2.01[2] / 1992
Platforms	Motorola 68030
Kernel type	Monolithic
License	Proprietary

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Bundled with the Amiga 2500UX and Amiga 3000UX, Commodore's Unix was one of the first ports of SVR4 to the 68k architecture, and this level of compliance was emphasised in marketing materials such as the company's "Born To Run UNIX SVR4" brochure.^[3] The Amiga 3000UX provided the OPEN LOOK graphical environment,^[1] with the machine reportedly featuring on the Sun Microsystems and Unix International stands at the 1991 Uniforum show, ostensibly as a consequence of Commodore's adoption of these exhibitors' technologies.^[4] An earlier Amiga-based graphical Unix system had reportedly featured on the AT&T booth at the Uniforum Fall '89 show.^[5]

The Amiga 2500UX had originally been described from COMDEX Fall 1988 show coverage as a 14.3 MHz Motorola 68020-based system with 80 MB hard drive and 150 MB tape system, fitted with 5 MB of RAM and featuring the Motorola 68851 memory management unit and Motorola 68881 floating-point unit (FPU). The "full implementation" of Unix System V was to be offered with the machine.^[6] A premature report had emerged of a version of Unix running on the Amiga 2000 at a separate October 1988 event,^[7] due to an X Window System implementation for AmigaDOS having been mistaken for a graphical Unix system.^[8] As the release of the Amiga 3000UX approached, the hardware requirements for Amiga 2000 systems running Unix were refined further, demanding an accelerator card providing a 68030 CPU and 68882 FPU, such as the A2630, more than 100 MB of hard drive storage, and a tape drive for installing the operating system. Thus, the Amiga 2500UX itself was based on the A2500/30 variant of the Amiga 2500.^[9]

Although the Amiga 3000UX could deliver a "responsive" experience, performance in the graphical environment was nevertheless described as being "on par with a slow 386 machine running SCO Open Desktop".^[10] Another evaluation of version 1.1 of the operating system described the X Window System performance as being "monochrome and slow as molasses", with an improved version 2.0 of the system to be made available, providing colour support in conjunction with the A2410 graphics board.^[11] This board was launched later in 1991, offering a 1024 x 1024 resolution with 8-bit colour depth,^[12] having been first announced in late 1988 as a collaboration with the University of Lowell.^[6] The card, based on the TMS34010, had previously been demonstrated at the Uniforum Fall '89 show.^[5]

The Amiga 3000UX's base price of US$4,998 (approximately US$11,200 today),^[13] rising to a reported $7,713 with graphics board (priced separately at around $1,000^[14]) and colour monitor,^[10] was not especially attractive compared to other Unix workstations at the time. Bt the end of 1989, around a year before availability of the Amiga 3000UX, vendors such as Hewlett-Packard and Sun had already launched 68030-based models aimed at the low-end of the market. The Apollo DN2500, positioned as an entry-level workstation with monochrome display by HP's Apollo division, cost only $3,990 for a diskless model or $5,490 with hard disk, eliminating the distinction between workstations and personal computers in pricing terms.^[15] The Sun 3/80 cost $5,990 for a comparable entry-level product.^[16]

RISC-based competitors offering superior performance were also already available at similar price levels as competition increased, such as the DECstation 2100 (reduced to $5,950), and numerous SPARC workstations were anticipated at this $5,000 price point during 1990.^[17] Sun's SPARCstation 1, introduced alongside the 3/80,^[18] had cost $8,995 for the diskless version in 1989.^[16] By the end of 1991, models such as the Sun SPARCstation IPC would cost $6,695 for a model similarly specified to the A3000UX in terms of memory, disk capacity and display, yet offer considerably better performance.^[10]

Commodore's product marketing manager indicated that the machine was intended to compete with machines from NeXT and Apple's A/UX, conceding, "We really don't see ourselves as being competitive with Sun."^[19] However, within a year of its launch, the Amiga 3000UX's 68030 was already considered "one whole generation behind" the 68040-based NeXTstation, priced from $4,995 with greyscale display, $7,995 with colour display.^[20] Later entry-level workstations from established vendors upheld their aggressive pricing while increasing the performance gap. For example, the Personal DECstation 5000 Model 20 provided a newer CPU and was priced from only $3,995 for a diskless configuration, with the faster Model 25 being available in a colour display configuration with hard disk for $8,495.^[21]

Unlike Apple's A/UX compatibility layer for System 7 applications, Amiga Unix contains no compatibility layer for AmigaOS applications. Prior to the system's release, Commodore had merely indicated that the company had been "discussing" such application support.^[5] With few native applications available to take advantage of the Amiga's significant multimedia capabilities, it failed to find a niche in the competitive Unix workstation market of the early 1990s beyond certain targeted deployments. For instance, computer science students at Virginia Tech were obliged to purchase the Amiga 3000UX to pursue their studies,^[22] with students offered a base model providing 4 MB of RAM, a 100 MB hard disk, and colour monitor for around $4,000.^[23]

Unlike typical commercial Unix distributions of the time, Amiga Unix included the source code to the vendor-specific enhancements and platform-dependent device drivers (essentially any part that wasn't owned by AT&T), allowing interested users to study or enhance those parts of the system. However this source code was subject to the same license terms as the binary part of the system – it was not free software. Amiga Unix also incorporated and depended upon many open source components, such as the GNU C Compiler and X Window System, and included their source code.

Like many other proprietary Unix variants with small market shares, Amiga Unix vanished into the mists of computer history when its vendor, Commodore, went out of business. Today, Unix-like operating systems such as Minix, NetBSD, and Linux are available for the Amiga platform.

• Atari TT030, Unix workstation from Atari