68kMLA Classic Interface

Just a thought... is the button broken?

Anyway, the fact that the handler ID is 0x04 means you're using a system new enough....

I'm not familiar with the program, but try setting it to listen, then clicking the right button. See if data received says anything.

Edit - thinking about it, you need to read the registers in the mouse with the right button pressed and not pressed. ADB is mostly driven by the host polling the peripherals. I'm not familiar enough to remember what exactly needs doing.

I find it easiest to open up “ADB Record” from the Window menu. When I move around my Pippin controller (which acts as a 2-button mouse by default) I see something along the lines of:

Poll Data Count:       $02
Data Buffer Contents:  $80 80

It looks like the data being sent is something like:

struct MouseListen {
    int8_t left : 1;
    int8_t y : 7;
    int8_t right : 1;
    int8_t x : 7;
};

This machine is on System 7, so no contextual menus. I’m not sure if they would work out of the box.
One thing to be aware is that some devices need to be told to provide more information. The controller’s other buttons don’t appear in the data and won’t unless told. I think the extended keyboard is like that too.