While trying to port PDOS/386 to the Amiga, PDOS-generic was born (both at http://pdos.org).
While investigating the BIOS that the Atari has, for a possible PDOS port, a technique was eventually invented to intercept (sort of) traps (interrupts) without needing privilege.
That has now allowed an Atari mini-clone to be created. Executables can be found in the last message here:
https://atari-forum.com/viewtopic.php?t=43832
You can run the mini-clone using qemu-m68k (user, not system) on any Linux platform.
Note that this is using the 68000 processor.
The technique used to detect this is a PDOS-generic environment should also be able to be used to run MVS executables. ie make R1 x'ffffffff' and then have the real value and more in R2. Or some variation such as if R1 is an odd number, then subtract 1 and look for extra info in R2 or in some unusual spot off R1.