Wow, that board is something quite special!
Rather slim pickings on OSes it seems...apparently that NT port was really early work, so it wouldn't be usable even if it existed.

Information on this page: http://www.geekdot.com/category/hardware/inte … olivetti-cp486/
seems to suggest its purpose might have been to accelerate graphics (as i860 was ill-suited for general-purpose OS).

Also on that same site, this page may be of interest (see the part about "Xnix"):
http://www.geekdot.com/myriad-dash860/

According to this thread (from 2001!) an uClinux port exists:
http://lkml.iu.edu/hypermail/linux/kernel/0112.1/0264.html

But it seems there is no mention about i860, only i960:
https://web.archive.org/web/20010812190449/ht … ma/uClinux.html

Here's some info:
https://www.osti.gov/servlets/purl/6167668

Oak Ridge did trials on clusters of these things with 386 'SRM' running Sys V Unix 3.2. The i860s run with a "simple OS kernel" NX, which accepts call from specially compiled C Fortran code running on the SRM.

Assuming a board like this uses the 486 as "SRM", it sounds like you should be able to do something with Sys V Unix 3.2 with specific compilers for i860.

Other paper:
https://esahubble.org/static/archives/stecfne … _stecf_0019.pdf
http://adsabs.harvard.edu/full/1993ASPC...52..570A

This is someone at ESO playing around with an add-in board with i860 in a SparcStation 2 to correct optics issues with Hubble space telescope. Different host, but same concept. Here an "MESL Hostmode Library" is installed, which again allows compiling Fortran and C code on the host system to run on the i860.

Intel blurb:
http://electro.fisica.unlp.edu.ar/arq/downloa … _Intel_i860.pdf
"A Unix V/386 or OS/2 hosts the application accelerator. which includes a runtime operating environment that maps I/O re- quests back to the host processor. A multiprocessing version of Unix System V Release 4.0 is under development for the i860 CPU. This is a joint effort by AT&T, Convergent Technologies, Intel, Olivetti, Prime Computer, and others "

Interesting, but the i860 is not included as a coprocessor in this system, it can switch the main processor betwenn 486 and i860. The boards boots with the 486, but the i860 can be activated by software to take over the full controll, and can give it back. So it is possible to run a native i860 OS, if that would be available.

This chip was also interesting for me as I own a single i860, but I've never heard about any dedicated motherboard for this CPU. The architecture of this chip is also interesting. It could do "SIMD" back when 486 was not able to perform such operations and thus it could increase the speed of 3d rendering.

winuser_pl wrote on 2021-01-05, 16:01:

This chip was also interesting for me as I own a single i860, but I've never heard about any dedicated motherboard for this CPU. The architecture of this chip is also interesting. It could do "SIMD" back when 486 was not able to perform such operations and thus it could increase the speed of 3d rendering.

Yes, actually on that geekdot site in the comments section there was an anecdote of someone who had demonstrated using that chip as a rudimentary 3D accelerator (thus gaining a job for himself).
Too bad it's just an anecdote...that could be interesting to see in action 😁

Reading the geekdot link posted by mr.cat, the CP486 page has a small manual and down the page for the LSX-5010 system there are images for a config and diagnostic floppies.
http://www.geekdot.com/category/hardware/inte … olivetti-cp486/
The CP486 manual has a list of compatible OSes.

The geekdot link in the 2nd post has manual and software for the Hauppauge card
http://www.geekdot.com/hauppauge-4860/, which are also available at http://edv-janssen.synology.me/ct_treiber_ser … prods/files.htm
This card has utilities to run programs on the i860 from the Dos or Unix host system.

Someone nicely shared a version of the Unix for the i860 with me, I can't publicly share it but I'll send a PM to 1ST1 to try some stuff.

Also the Walnut Creek Sys V r4 cdrom on archive.org has a few software sources for the i860 platform, like binutils, gcc and others.

There may also be utilities for AIX and OS2 that can use i860

Does the x86 CPU transfer control to the i860 then halt until control is handed back?