I would like to make a mouse.xr version working with my PS/2 mouse hardware.

After your studies, will you have enough information to describe how I can modify the mosue.xr with my (approximately 4-6 instruction length) mouse reading code,
and how I can place the coordinates to the right places in mouse.xr, from where mouse.xr can give it forward to the applications ?

Here you have a 3178 bytes version Mouse.xr modified to auto-start. It lets you open a mouse channel without first send ":pb".

It works, at least on the partially approached mouse function of the emulator.

Thanks. I hope it is only the beginning...

How can I read that code?

Need a chip programmer which are support PIC chips.
Anyway if you buy, then look one which are also support Flash ROMs, will be useful

There is this Chinese programmer on Ebay.es that claims to access up to  12.000 chips.

It is more cheap if I buy it from China.

Ok, I  opted for a HK based vendor that sells more adapters but arrives later..... min 15 days but max 30.....

The modification made on version 1.1 doubles the movement readed from the mouse, but only in values greater than 1 or -1. Then it adds some "velocity" to the cursor.