I am not sure this is what you are interested in, or not and I should go back to sleep
Yes, I was interested in this,
and more.
I think you left out wich bit (or value) in a b5 port write (alias joystick direction) is wich bit of the 4 bit "half byte" ... there are many combinations,
and I do not know an other thing, too:
You specified the order of the "half bytes" like XHigh,XLow,YHigh,YLow ... but its a looped thing ...
When I'm a microcontroller, I know the order, which one to send after which one, okay,
but I do not know "when the first is", or "which are just now" ...
So, I just turned on the EP, mouse.xr starts run, reading XH,XL,YH,YL again XH,XL,YH,YL again XH,XL,YH,YL again XH,XL ...
and NOW, I connected the converter (the boxsoft, or my microcontroller thing), mouse.xr will want to read YH next, because that is the next in its order,
how will I know which one is wanted by mouse.xr ?
When I know it, I will know the next one from the order ... But what is the current, at the connectiong of the interface ?