...and, actually, after some more digging, I found out that the interface is a "Steinberg MIDI2" interface, and that it should be compatible with Datel / JMS / C-Lab / Siel. So I should definitely try it out with something else than M64. It is this one: … r-the-c64/

The sticker is ripped off on the one I have though, so that's why I didn't know at first which one it is.

Last edited by frantic (Jun 22, 2020 11:27 am)


...aaaaaaand now I tried it with some other software that supports DATEL as well (King Fisher's "Midislave Manager") and the interface didn't work there either.

Conclusion: The interface doesn't work.


Hey thanks for trying

Do you know if these devices actually work with an ultimate 64 anyway? I borrowed a friends datel midi cart and ran cynthcart as a prg and it didnt work. Worked in my breadbin though running on an sd2iec.. perplexing.


I haven't used the Ultimate64 personally, so I don't know much about it. As far as I have understood, the general idea should be that it should be fully compatible with the C64, but maybe it is more like 99% compatible in actual practice. However, in this case I guess it could also be the case that the Ultimate64 emulates a cartridge at the same time as you have the midi cart inserted. If so, there may be a conflict between the emulated cartridge and the MIDI cartridge. The DATEL cartridge uses the following addresses:

MIDIcontrol = $de04 ;write-only
MIDIstatus  = $de06 ;read-only
MIDI_Tx   = $de05   ;write-only
MIDI_Rx   = $de07   ;read-only

If the emulated cartridge interferes with this in some way, the MIDI cart won't work. Then you would either need to disable the emulated cart, or your would need to use a cartridge ROM that doesn't interfere (I think the Retro Replay ROM may be worth a try for example).

(Cartridges such as Final Cartridge, Action Replay, Retro Replay, and so forth generally also use the $dexx adress range. I seem to remember that I used a cartridge port expander at some point, to get a MIDI cart working at the same time as an action replay/retro replay cartrdige, and the cartridge port expander allowed me to shift the MIDI interface to the $dfxx range instead. Then I also had to modify the software I used so that it used the $dfxx adresses to communicate with the MIDI interface, instead of $dexx.)

Last edited by frantic (Jun 22, 2020 8:47 pm)