Irken Labs has released a successor to their JVS-PAC, which is basically a keyboard encoder for JVS IO boards, so you can use the direct JVS wiring standard on, say, a MAME PC without re-wiring anything. The advantage of JVS-PAC 2 compared to an ultimarc JPAC is, for example, direct usage of the JVC IO board; enabling you to use a kick harness and the integrated audio amplifier. The original JPAC requires external solutions for these problems.
Source: https://irkenlabs.com/jvs-pac2/introduction
Thanks to Jockel for the help with this article.