One of the risks with new instruments is that you might put a lot of work learning how to play something that then is discontinued. In the case of the jammer, things are worse because it was discontinued five years before I even got into the instrument. As I see used Axis-49s come up on resale sites I've been making lowball offers, as politely as I can, trying to collect a few spares, and at this point I have three and a half. [1] While my main goal with these is insurance against a future where mine breaks and I can't fix it, they don't need to stay on my shelf: I've been lending them out to people who want to play with the layout.

You can't use it without a MIDI mapper, though, because while I've rearranged the physical keys, that doesn't make it send different MIDI signals. I was trying to help someone get set up with one, and it turns out that the state of MIDI mappers for non-programmers isn't that great. Plus, with 98 keys, that's a lot of data entry. So I've made a stand-alone version for Mac: source code, executable program.

It's a quick cut-down version of the code behind my rhythm stage setup that looks for an Axis-49 and presents a virtual MIDI device (jammer) that produces the mapped notes. There are two binaries, one for holding the device with (non-functional) transpose keys up, the other with transpose keys down.

If you sometimes play with sharp-key instruments and other times play with flat key ones, you can turn the device over and use the other binary, with a transposition MIDI mapper. This lets you have a range from F to B (F, C, G, D, A, E, B) in one orientation, centered on the key of D, and Db to G (Db, Ab, Eb, Bb, F, C, G) in the other, centered on the key of Bb, in the other.

[1] Three good ones, and one that's too old to go into "selfless" mode and so is effectively only half a keyboard.