The E-MU Morpheus and UltraProteus were designed by Dave Rossum to use the (then new) 'Z Plane' filter concept; however, due to technical limitations of the time they were quite complicated to control and didn't explore the concept in its fullest. I suppose the next question would be, why were there two separate modules released with different names but similar features? I think the Morpheus module was rebranded and sold as an 'UltraProteus' and given more general purpose ROMpler sounds to be more marketable. This is in fact why I bought an UltraProteus: to get access to its specific and unique ROMpler sounds, but the Z Plane archtiecture is a nice bonus on top of that.
Fast forward to 2017 and Dave Rossum has released a modern incarnation of the technology in a new module: https://www.rossum-electro.com/products/morpheus/, for all intents and purposes it would probably be best to pick one of these up for Z Plane, rather than the legacy modules... unless you're really itching for those ROMpler sounds.
Note: despite the name, "MorphEdit" also works with UltraProteus modules as they are practically identical with the exception of the samples and presets.
It looks like someone published the original source code on GitHub (unrelated to the original author): https://github.com/SaintFlipper/morphedit
Unfortunately the build quality of the Morpheus/UltraProteus leaves a little bit to be desired. They use cheap capacitors, a horrible display etc. It's highly advised that you get them recapped if they've not been already.
If you wish to upgrade the display to something more reasonable, 'luxdisplays' from the UK sells replacement modules: https://www.ebay.com/itm/154116321180, their eBay page is: https://www.ebay.com/usr/luxdisplays. If the listing ever changes or gets relisted, you can go to their store page and search "E-mu Orbit / Procussion / Vintage Keys / Morpheus / Planet Phatt OLED Display !"
I tried looking for service manuals but came up clean; they definitely exist somewhere out there though but must be rare or neglected/forgotten. With that said there are a few known procedures:
Reset Procedure: while powering on the unit, hold down both cursor buttons (< | >) to access the diagnostic page. Choose initialize and reboot from the diagnostics page.
Diagnostics Procedure: while powering on the unit, hold down (Master) and ([Right] Cursor). I believe this automatically runs diagnostics?
Note: user data in memory will be wiped, MIDI test will fail without anything plugged into the MIDI ports.
Out of boredom (and perhaps a little bit of paranoia?) I looked up common issues people were having from the Morpheus and UltraProteus modules. There did seem to be a few common things but with no direct solution(s). As these are digital using proprietary firmware and ICs, there's only so much you can do without schematics.
A new development with these, seems to be bad contact with the sockets and the various ROMs and ICs contained therein. If your unit is failing to initialize (braindead) you may want to try reseating the ICs or cleaning the sockets.
'oscillator Sound Design Studio' had some pretty nice demos of the units, just thought I'd share them here in a succinct list in the event anyone wanted to get a feel for how these modules can sound: