MachTen
Unix-like operating system
From Wikipedia, the free encyclopedia
MachTen is a Unix-like operating system from Tenon Intersystems. It is based on the Mach kernel, 4.4BSD, GNU programming tools, and the X Window System. It runs not natively but as a classic Mac OS application program in a virtual machine.
| MachTen | |
|---|---|
| Developer | Tenon Intersystems |
| OS family | Unix-like BSD |
| Working state | Discontinued |
| Source model | Closed source |
| Latest release | 4.1.4 / February 2000 |
| Supported platforms | Macintosh: Motorola 68000, then PowerPC |
| Kernel type | Microkernel |
| License | Commercial, proprietary |
| Official website | tenon |
Unlike Apple's contemporary A/UX, which boots natively from a dedicated partition, the MachTen application shares the host's Hierarchical File System (HFS).[1] Tenon released the original version for Motorola 68000 processors in 1991, followed by Power MachTen for the PowerPC architecture in 1995.[2] The product was discontinued in October 2001, citing the successor Mac OS X.[3]
History
MachTen development started in 1989, and the first release in 1991 has Mach 2.5 and 4.3BSD-Reno.[4][1] The second release in 1992 has the X Window System. Early releases do not support System 7,[5] and later versions support System 6 with MultiFinder, and System 7.[6]
In 1993, release 2.1 introduced virtual memory, memory protection, and an improved paging model for Mac applications.[7] Since then, MachTen was published as Personal MachTen, and Professional MachTen with development tools and virtual memory.[8] Release 2.1.1 was announced in 1994, introducing virtual memory support for Motorola 68040.[9] Professional MachTen for Motorola 68000-based Macintoshes ended with release 2.3,[10] announced in 1996 for low-cost web servers.[11]
In 1995, Power MachTen was launched for Power Macintosh, with release 4.0 supporting shared libraries and memory-mapped files, and a 4.4BSD-based, POSIX-compliant distribution.[2] Release 4.1 was in March 1998,[12] and 4.1.1 in July 1998 with discounted prices.[13] Power MachTen lacks some of the features of Professional MachTen (including true virtual memory and memory protection) but is PowerPC native and is compatible with Mac OS 9 through its final version, 4.1.4, released in February 2000. Tenon discontinued MachTen in October 2001, citing the release of Mac OS X as a successor.[3]
Overview
Unlike Apple's A/UX, which boots natively and runs System 7 as a Unix application based on a Unix port of Mac OS Toolbox, MachTen runs an entire Unix operating system as a Mac application.[6] This approach hosts the BSD Fast File System on the Hierarchical File System (HFS), imposing HFS limitations on Unix, including 31-character filenames. Other filesystems such as Network File System volumes are unaffected. However, this implementation allows Unix programs transparent access to any Mac files and without a dedicated partition.[1]
Filesystem performance in the shell is reportedly around three times slower than A/UX and six times slower than Finder equivalents, though Finder operations are only marginally slowed down. However, Finder operations were only marginally slowed alongside MachTen, in contrast with a two-fold slowdown in A/UX. MacUser described file-intensive GNU C Compiler performance on MachTen as "painful" in version 2.0.[6]
Other integration features include embedding the Internet Protocol in AppleTalk network packets, which enables the traditional Unix networking such as FTP, Telnet, remote login, and Sendmail. This effectively integrates TCP/IP with LocalTalk without disrupting AppleTalk.[1] However, this encapsulation results in lower transfer rates than A/UX and "sluggish" performance.[6]
MachTen does not require a memory management unit, broadening the audience over A/UX's hardware restrictions. In its first version, this enables Unix programs to "bring down the entire system". so later versions have memory protection and paging for Unix programs on MMU machines.[10] Early versions lack virtual memory but compared to A/UX's requirement of a "high-end Mac and a lot of disk space", MachTen has lower system requirements and greater Mac application compatibility.[1] Later versions introduce memory protection and paging for Unix, for MMU systems.[10]
Although MachTen reportedly used the Mach 3.0 microkernel since MachTen version 2.0,[5] reviewers noted that Mach 3.0 was yet to be adopted, along with usage of 4.4BSD that would be free of AT&T code[6], this being of concern with the UNIX System Laboratories, Inc. v. Berkeley Software Design, Inc. lawsuit ongoing.[5] Other Mach-based systems were identified as competitors, including the AIM alliance's PowerOpen Environment for PowerPC in which OSF/1 was planned to "combine A/UX and AIX",[14] and the including 68k-based MacMach from CMU which had created Mach. However, MacMach's licensing restrictions made the product unattractive outside of academia and enterprises.[6] IBM and Apple later proposed a Mac OS personality for the prototype Workplace OS which is based on Mach 3.0.[15]