The Ultimate Windows NT MIPS VM

Posted on November 7, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

In my previous posts I covered NT MIPS on QEMU Jazz and on the Siemens RM-200. Time for the ultimate one!

Behold! Windows NT 4.0 Server with 4-way MIPS SMP!

Windows NT 4.0 Server MIPS Task Manager with 4 CPUs at 100% and NTFETCH showing 4 x MIPS R4400 — 4 CPUs, all busy

Specs: Siemens Nixdorf RM300-C, 4 x MIPS R4400, 128MB RAM, Cirrus 1280x1024 256 colors, AMD PCnet

Each guest CPU runs on its own separate host core. Real R4400 boards had at most 2 CPUs, but the firmware and the NT HAL handle 4 just fine. It has to be Windows Server, as Workstation only supports 2 CPUs.

Windows NT 4.0 MIPS boot screen: 4 System Processors [128 MB Memory] MultiProcessor Kernel

CPU idle detection! NT’s idle loop just spins. LEMU detects it and halts the CPU instead. On my Mac the idle VM uses ~10% of one host core. Without it the same idle desktop burns 3 full cores!

Seamless mouse! Remember the mouse issues from the Jazz post? All solved now thanks to the vmmouse driver. No more mouse grab, the pointer just moves in and out of the window, and the scroll wheel works!

Animation: the mouse pointer moves in and out of the QEMU window running Windows NT 4.0 MIPS without a mouse grab — Look ma, no mouse grab!

Ready to run portable image for macOS (Apple Silicon), Linux x64 and Windows x64. Unpack and run run.sh or run.cmd. At “Hit any key to continue” press Enter twice. NT logs on by itself as Administrator / password.

Download: https://files.42718.net/mirror/tenox/os/winnt/VMs/qemu-mips/nt4srv-rm300-smp4-qemu.tar.lz

Source (LEMU, my QEMU fork): https://github.com/tenox7/lemu

Have Fun with Virtualization!

AIX 4.3.3, 5.1, 5.3, 6.1, 7.1 on QEMU w/Graphics!

Posted on November 7, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

AIX on QEMU is nothing new. Neozeed ran AIX 4.3.3 years ago on Artyom Tarasenko’s QEMU 40p fork — but it was serial console only, no graphics, and the emulated CPU pinned your host at 100%. Recently I did AIX 3.2.5 and AIX 4.1.5 with a local graphics console. Now we have the rest of the line!

Behold! AIX 4.3.3 all the way to 7.1, every one booting to a graphical CDE login on the emulated framebuffer. AIX 7.2 is only serial console.

AIX 4.3.3 graphical CDE login screen — AIX 4.3.3

AIX 5.1 graphical CDE login screen — AIX 5.1

AIX 5.3 graphical CDE login screen — AIX 5.3

AIX 6.1 graphical CDE login screen — AIX 6.1

AIX 7.1 graphical CDE login screen — AIX 7.1

The older releases (4.3.3, 5.1) run on the emulated RS/6000 7020-40P, the newer ones (5.3, 6.1, 7.1, 7.2) on an emulated pSeries. And no more burning 100% CPU, we have full IDLE detection.

All images are ready to run and portable, with QEMU binaries for Linux, macOS and Windows. Just unpack and run. Grab whichever you fancy:

Have Fun with Virtualization!

Ultrix 4.5 on GXemul w/Apps!

Posted on November 6, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

Ultrix on gxemul is nothing new. The DECstation is gxemul’s oldest and most complete machine mode, and it has run Ultrix for over 20 years. What’s new is Rico’s fork, which fixes a ton: the real KN02-AA PROM boots, the LK201 keyboard works, faster NAT, NFS, and best of all high resolution graphics!

Behold! Ultrix V4.5 in 1280×1024 on an emulated DECstation 5000/200 (3MAX, R3000, 128 MB) with the HX (PMAGB-BA) color frame buffer:

Ultrix 4.5 DECwindows desktop, DECterm showing uname -a: ULTRIX ds5000 4.5 0 RISC — Ultrix V4.5 on an emulated DECstation 5000/200

The high resolution HX is new here. Stock gxemul topped out at a lower res frame buffer. Rico emulated the HX’s SFB drawing chip — fills, stipples, lines, copies, all 16 raster ops — so Ultrix’s X server drives it directly. uname says it all: ULTRIX ds5000 4.5 0 RISC.

Best of all, the image comes with a pile of cool software already installed and ready to run. Let’s look at some apps!

Mathematica 2.2 running on Ultrix 4.5 — Mathematica 2.2

CorelDRAW 3 running on Ultrix 4.5 — CorelDRAW 3

FrameMaker 2.1X running on Ultrix 4.5 — FrameMaker 2.1X

There is more under the hood: gcc 3.0.4 and the GNU tools, bash, vim with Motif, xv, and even NCSA Mosaic for some retro web browsing. Ultrix V4.5 (Rev. 47) itself is patched up with DEC’s late 1997 Y2K fixes.

As usual I have prepared a ready to run, portable image with gxemul binaries for Linux, macOS and Windows. Just unpack and run run.sh (or run.cmd on Windows), type boot at the >> prompt, and log in as root with password ultrix.

Download: https://files.42718.net/mirror/tenox/os/ultrix/virt/decstation5000-ultrix45-gxemul.tar.lz

Rico’s fork: https://github.com/rpajarola/gxemul

Have Fun with Virtualization!

AIX 4.1.5 on QEMU

Posted on October 28, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

AIX on QEMU is hardly any news. It has been done over and over again. Especially thanks to Artyom Tarasenko and subject to even more posts by Neozeed. However it was mostly plagued by having only serial console and using outdated QEMU. For a long time I wasn’t able to run it. Had to fire up some IBM rust if I wanted to build/test something on AIX. Lack of local UI was also pain. AIX 4.1.5 is full of cool GUI software, CATIA, Corel Draw, Word Perfect, FrameMaker, Lotus Notes, not to mention VisualAge! I know that you can connect to it via Xephyr/Xnest etc, but having a local console is way better!

Behold! AIX 4.1.5 in a full glory on emulated IBM RS/6000 7020-40P with PowerPC 604 and GXT110P video adapter. Also featuring front the panel display:

Let’s look at some cool apps!

I have prepared a ready to run, portable QEMU image with binaries for MacOS/Linux/Windows. Download and run: https://files.42718.net/mirror/tenox/os/aix/Virtual/aix415rs6k-qemu.tar.lz

Have Fun with Virtualization!

PS You may also be interested in AIX 3.2.5 in QEMU

Personal Computer Simulator/6000

Posted on October 27, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

Previously I ran a whole series of articles about vintage hypervisors and dos emulators for unix. Some of them: Merge, VP/ix, Wabi, SoftWindows, etc. Today we have a special gem: PC Simulator on AIX 3.x on POWER!

I recently virtualized AIX 3.2.5 on QEMU. While browsing Info Explorer I noticed this curiosity:

As you can imagine in 2026 this would be pretty much unobtanium relic. Fortunately Plamen, now confirmed having a time machine was able to score this:

PCSIM – Personal Computer Simulator/6000

Above is a plain text / ascii mode.

There also is X11 version!

Capable of VGA graphics!

Microsoft Flight Simulator on PCSIM on AIX 3.2 on QEMU

Usage: pcsim. For X11/VGA mode: -dmode VGA. The pcsim can be launched with PC BASIC bios, or load DOS from floppy disk or HD image. For hd image: -Cdrive /usr/local/pcsim/pcdos5.img – In order to quit press ESC + type pcsim.

The pcsim tarball is here: https://files.42718.net/mirror/tenox/os/aix/3.2/pcsim-1.2-aix325-full.tar.Z

Data General DG/UX on 86Box

Posted on October 26, 2026 by tenox

(This is a guest post of Antoni Sawicki aka Tenox)

This is not strictly new. DG/UX worked on 86box before, but only partially. Low resolution and no networking made it almost unusable. Now it all has been patched up!

Ready to run image available here: https://files.42718.net/mirror/tenox/os/dgux/Virtual/DGUX-R4.20MU07-86Box-20261010.tar.lz

AIX 3.2.5 in QEMU

Posted on October 24, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

Behold! AIX 3.2.5 now runs in QEMU!

Along with full X11 AIXwindows Desktop support on emulated GXT150L.

Also featuring the 3 digit diag display with key switch for service mode! The display is addressable from the os via /usr/lib/methods/showled.

There are some gnu/pds apps in /usr/local/bin.

The exact machine emulated is 7006-41T (POWERstation 41T, 1994) + GXT150L

The QEMU branch: https://github.com/tenox7/qemu/tree/aix3

Ready to run portable QEMU image: http://files.42718.net/mirror/tenox/os/aix/Virtual/aix325rs6000-qemu.tar.lz

Have fun with Virtualization!

Updates:

OS/2 PowerPC Edition on QEMU

Posted on October 20, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

Yesterday I featured a QEMU branch capable of booting Windows NT PowerPC. I was asked in comments if this by any chance also supports OS/2 on this architecture. The answer is: YES!

Here is the result:

Here is a link to a ready to run image: http://files.42718.net/mirror/tenox/os/os2/virtual/os2powerpc-qemu.tar.lz – it takes a little bit of time appearing stuck on PowerPC logo with a warning sign, but not too worry it will boot up.

The branch is https://github.com/tenox7/qemu/tree/powerpc

You can learn more about OS/2 PowerPC edition at OS/2 Museum.

Windows NT 4.0 PowerPC on QEMU

Posted on October 19, 2026 by tenox

(This is a guest post by Antoni Sawicki aka Tenox)

Another day another NT QEMU post. This time we have stock Windows NT 4.0 PowerPC running on QEMU, with complete emulation of the BIOS / Firmware and everything. Networking and 1280×1024 resolution.