The following blog entry refers to files at

While not (yet) made accessible, this README entry describes the contents being assembled and subsequent maintenance of the MACH386 product.

February 1, 2018

These files contain the floppy images and scanned documentation for the
Mt XINU Mach386 binary distribution for "MACH and BERKELEY UNIX for i386".

This is the full 3.5" floppy distribution, and includes the Mach 3.0 CMU
product as well as the Mach 3.0 DUI (DOS server). The build/release
date of this product is March 23, 1992.

The usefulness of this software is questionable, for a number of reasons:

  • Mt XINU only provided media for the base system. All
    further updates, bug fixes and additional functionality,
    were provided electronically only. There are many bugs
    and issues in the base system, and no source is available.
  • Mach386 only supports a very limited list of hardware,
    primarily ISA bus-based hardware and early IBM-PC disk
    size limitations.
  • There are no source repositories of Mach 2.6 software, upon which
    Mach386 is built. Neither the source nor the binaries
    have been found. Mt XINU stopped selling software in the
    mid 1990's, and no known archives exist. There was at least
    one later release of Mach386, dated August 6 1992, that
    would have had later software fixes and updates.

The following are included in this binary product distribution, as
received from Mt XINU in 1992:

  • MtXinu-Mach386-Advertising_Brochure-1992-OCR.pdf
    This is a color advertising brochure describing the Mach386
  • MtXinu-Mach386-Release_Notes-March_23_1992-OCR.pdf
    This addendum describes known problems with this distribution.
  • MtXinu-Mach386-Installing_and_Operating_Mt_XINU_Mach386.pdf
    This yet-to-be-scanned document provides the installation
    and operation procedures of the distribution.
  • MtXinu-Mach386-Mach_3.0_and_DUI_Package-Manual-November_13_1992-OCR.pdf
    This document provides Mach 3.0 and the Mach 3.0 DUI
    package installation and operation instructions.
  • CMU-Mach_3.0-Setup_for_Mach_3.0-Mary_R_Thompson-April_1_1993-OCR.pdf
    This is a copy of a paper written by Mary R. Thomson, of
    Carnegie Mellon University, describes set-up and booting of
    the Mach 3.0 kernel on a Mach 2.5 base-installed system.
  • MtXinu-Mach386-Product_Description-August_6_1992.txt
    Mach386 Product Description for a later August 6, 1992, release.

The following 1.44MB 3.4" floppy images have been imaged. They comprise
the full Mt XINU Mach386 distribution dated March 23, 1992:

  • MtXinu-Mach386-Bootstrap-For_Base_MB920331020.FD1440.dsk
    This is the installation bootstrap floppy image.


  • MtXinu-Mach386-Filesystem-For_Base_MB920331020.FD1440.dsk
    This is the installation bootstrap filesystem.


  • MtXinu-Mach386-MB920331020-Base_System-Floppy_01_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_02_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_03_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_04_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_05_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_06_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_07_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_08_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_09_of_10.FD1440.dsk
  • MtXinu-Mach386-MB920331020-Base_System-Floppy_10_of_10.FD1440.dsk
    These floppies contain the base system distribution.


  • MtXinu-Mach386-MN920331034-Networking-Floppy_1_of_2.FD1440.dsk
  • MtXinu-Mach386-MN920331034-Networking-Floppy_2_of_2.FD1440.dsk
    These floppies contain the Networking userland binaries,
    libraries, development (header) files and on-line documentation.


  • MtXinu-Mach386-MD920331030-On_Line_Documents-Floppy_1_of_2.FD1440.dsk
  • MtXinu-Mach386-MD920331030-On_Line_Documents-Floppy_2_of_2.FD1440.dsk
    These floppies contain the Mach386 on-line documentation
    (man pages, etc).


  • MtXinu-Mach386-MX920331007-X_Window_System-Floppy_1_of_9.FD1440.dsk
    These floppies provide X11 Window System binary and support
    and documentation distribution.


  • MtXinu-Mach386-M3921131020-Mach_3.0+DUI-Floppy_1_of_6.FD1440.dsk
    These are the add-on Mach 3.0 and DUI distribution files.

The floppies are direct images of each of the distribution floppies.
They were extracted using the UNIX dd(1) command as follows:

# dd if=/dev/fd0 bs=512x18 of=imagename.DSK

The distribution floppies utilize standard PC-compatible 1.44MB
3.5" recording format that the DOS and Windows 'FORMAT' command
produces. They can be written directly to formatted floppies
with the same dd(1) command method:

# dd if=MtXinu-Image.dsk bs=512x18 of=/dev/fd0

or other equivalent means on other platforms.

All of these floppy images have been verified and test-installed
on a basic 500mhz i386 system using an IDE/ATA disk (BIOS-configured
for 1023/16/63 Cylinder/Head/Sector limits). An ongoing attempt
to obtain an ISA Western Digital/SMC WD80x3 ISA ethernet adapter
continues to be pursued to determine if networking support can be

This particular distribution has broken SCSI support, and is not
fixable since the electronic updates from Mt Xinu are no longer
available to update the distribution.

I personally used this Mach386 (with updates from Mt Xinu) from
1991 through 1998. Despite its development-quality short-comings,
it proved to be robust enough to manage for me as a professional
platform and as a personal platform back in the days of network
communications through dial-up mail-based USENET and early CERFnet

If there are any questions or if you have access to additional
Mt XINU Mach386 or MACH 2.5/2.6 source or other Mt XINU information,
please contact me.

Scott G. Taylor
bub7734 at gmail dot com