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

February 3, 2018 UPDATE

I have found my last root dump and usr tar archives from 1996 which includes the
latest updates I was able to sup(8) from Mt Xinu in 1993. I will be assembling
additional distribution additions with the updated binaries and files. Included
in these updates from Mt Xinu are working SCSI support, additional userland and
GNU utilities and the Mt Xinu MSD 2.6 rebuildable/reconfigurable kernel.

I have also located the January 21, 1991 distribution floppies. However, there
are a number of unreadable floppy sectors in various locations of this set which
renders the entire distribution useless. Since the distribution sets are
effectively sequential chunks of compress(1)'d data, the loss of a block of
data in any of the floppy sets renders that set incomplete and a working
installation from it is impossible.

February 8, 2018 UPDATE

I've gotten networking working now. I'd been having great difficulty
with Mach386 in getting a working setup with the supported networking
cards. The only supported cards are the Western Digital/SMC 80x3 and
3Com 3c502 and 3c503 (EtherLink II) cards, all of which are ISA-bus

Despite the documentation showing supported IRQ/PIC configurations
with IRQ 2 (actually IRQ 9 in more modern hardware) and IRQ 5, it turns
out that the source for autoconf.c has all configuration options
hardcoded to IRQ 2/9. As it turns out, the motherboards I have
will not work setting these networking cards to IRQ 2/9.

The cards would successfully transmit packets, and the on-board
LEDs would indicate receipt of a packet, but the Mach386 kernel would
never see an interrupt and thus would never be able to load the
packet from the card.

After obtaining and failing to get a number of WD8003 and WD8013
cards working, and ultimately discovering this issue, I hand-edited
the vmunix kernel file. Having located the autoconf storage for the
configurations, I changed the IRQ configuration options for these
cards to IRQ 3, booted that modified vmunix, and I have ethernet
connectivity now.

There are some additional issues I'm working out with NFS, but I expect
these to be resolved in short order.

I will be pursuing SCSI functionality very soon now as well once I
receive working Adaptec AHA1542B cards I've ordered.

Additionally, I'm well underway in writing a sysload(8) replication
program that runs on modern UNIX. This replacement will be the basis
for a utility to generate new distribution media to facilitate updating
binary systems and generating a new release with the latest binaries
I have availab.e

I'm also working on getting the reconfigurable kernel generation files
working that will allow easier device configurations (rather than using
a binary editor as I've just done for the networking card configuration).

More to come...

February 9, 2018 UPDATE

Receipt today of a working Adaptec AHA1542B controller has provided
me the means to test and utilize SCSI support in Mach386.

Preliminary testing shows that the late-1992 Mach386 vmunix kernel
works well for SCSI disk. SCSI tape seems to have an issue wherein
it is writing an extra tape record when a tape device is closed after

This first SCSI Disk testing was performed with a Seagate ST15150N
Barracyda 4 drive. This drive is 4,294 Mbytes formatted, This is
exactly the 4GByte disk-size limit of the 32-bit Mach386 kernel.
The BSD UFS filesystem limit is 2GByte. Full testing of this drive
and the 4GB limit will occur in the next few days.

A 2GB (Max, for the BSD UFS architecture) can be created and mounted:

# df /mnt2
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/sd0h 1969518 2 1772564 0% /mnt2

The SCSI Tape testing was first performed with a Seagate STD2401LW DDS-4
tape drive utilizing a DDS-1 tape. Various DDS tape drives were
actually tested, but I settled on this DDS-4 drive once I realized
that the extra block being written (and read) from the tape was
not specific to a particular drive.

Additional drive testing with a Quantum 4000 (TH5AA-YF) DLT tape
drive indicates the same sort of problems. Additionally, preliminary
testing there shows that at 20480-byte block size, the 20480th
byte of the first block is being written or read back incorrectly
as that byte fails comparison to the original data.

There are definitely problems with the st.c SCSI tape driver.

Today I also successfully mounted an NFSv2 filesystem from a FreeBSD 11.0
server onto Mach386:

# mount mod5:/tiny /nfs
# df /nfs
Filesystem 1024-blocks Used Available Capacity Mounted on
mod5:/tiny -785220319 -1208500253 423279934 154% /nfs

Compare that to the server's reporting of that filesystem:

# df /tiny
Filesystem 1K-blocks Used Avail Capacity Mounted on
zpool1/tiny 12099681569 938983394 11160698174 8% /tiny

It will be interesting to see what issues arise.