In spring 2019 I started developing a patch for Max/MSP that could control all the parameters on my Korg Electribe ER-1 via NRPN messages. NRPN stands for "Non-Registered Parameter Number", and according to Wikipedia, NRPN "is part of the Musical Instrument Digital Interface (MIDI) specification for control of electronic musical instruments. NRPNs allow manufacturer-specific or instrument-specific MIDI controllers that are not part of the basic MIDI standard."
Figuring out the ER-1's NRPN protocol was not an easy undertaking; I found Korg's MIDI implementation charts to be pretty abstruse, and I couldn't find a lot of information elsewhere on the internet. Ultimately what cracked the code for me was using the MIDI Monitor app by Snoize to monitor all incoming MIDI signals from the ER-1. I figured out what all the numbers meant and built my Max patch to both process incoming parameter changes from the ER-1 and control the ER-1 from a user-interface built in Max (pictured above).
Korg released the ER-1 in 1999 in its series of other affordable grooveboxes, and I probably started using one shortly thereafter, as a teenager in the early 2000's. I've had it since then and have continually returned to it for its crunchy and metallic sounds. This patch allowed me to extend my capabilities with the ER-1, especially insofar as it has allowed me to create a great deal of independence between the 4 oscillators and the way they are behaving, turning the ER-1 into a self-contained modular synthesizer of sorts. As of writing this (April 2020, deep into the Coronavirus lockdown in NYC), I'm working on a project called "Music for ER-1," in which I'm writing a suite of Max patches to control the ER-1 using algorithmic processes to generate unexpected results from this superficially simple groovebox. At this point I've spent far more time and effort than would ever be reasonable to spend on this little groovebox, but I've had a lot of fun with this project and my quest to become the world's foremost ER-1 viruoso.