Kerberos is a MIDI interface for the C64 and C128 with integrated flash memory. With this cartridge for the expansion port you can connect MIDI devices like keyboards and synthesizer to your C64 or C128. The 2 MB integrated flash memory allows to save programs for quick start, which you can transfer over MIDI from a PC or Mac. The 128 kB integrated RAM can be used for programs as a memory extension. The cartridge provides an EasyFlash emulation as well, you can store an EasyFlash CRT image with up to 1 MB on it.
Pre-installed is a menu system to start the programs on flash and to flash new programs, and the following programs:
Sequencer software Pro-16, by Steinberg (with kind permission of the publisher). Of course, Steinberg doesn't guarantee anything or support this software anymore. A short German review of the software on Youtube. You can download the software and the manual in PDF format here, too.
SID Wizard, by hermit. The current version 1.7 support this MIDI interface. (project page)
Joe Gunn, the Gold Edition (with kind permission of the publisher, programmer homepage)
a special MIDI version of the Cynthcart software, which Paul provided for free now, too, see the Cynthcart homepage. See here for a handy overview of the MIDI CC commands and the keyboard mapping.