Forum member Mike Chambers has informed us an emulator he has recently re-worked on and completed in C when it was originally worked on in Basic and abandoned.
It's open-source, supports all 8086 and 80186 instrutions, emulates most of the standard PC hardware, uses image files for floppy/hard drive (like QEMU), runs on windows/linux (and OS X with a little tweaking of the source)..
It runs every version of DOS.
-complete 8086/80186 CPU emulation
-intel 8259 interrupt controler emulation
-hercules/CGA/MCGA/VGA emulation (lacks EGA and 640x480 4-bit VGA currently)
-disney sound source emulation
-in windows, it can use winpcap to emulate a network card... theres a special DOS packet driver designed for it that is on the fd-fake86.ima floppy image that comes with the windows download (PD.COM)
(no DMA controller or sound blaster emulation yet, but eventually...)
more info, downloads, screenshots, etc:
video of it playing Wolfenstein 3D:
^youtube's encoding messed up the audio pretty nicely for some reason. it sounds better than this. the video there sounds like its underwater or something.
it's also very fast, it rivals DOSBox for speed. depending on what's being emulated, it'll emulate between 25 million and 70 million instructions/sec on my 3.2 GHz AMD Phenom II X4 955.
Download the emulator on Zophar's Domain here