Tube🌿Timewelp, how'd i get into THIS situation? let's rewind...
on the back, we have the usual semi-cursed 13W3 video connector and the Sun keyboard connector. where am i going to find a Sun keyboard?
i just happen to have one, new in box! i bought this years ago at Weird Stuff Warehouse when they were still around. i have no idea why, but i'm glad i did.
however, they have RJ11 connectors and the keyboard (which is where the mouse plugs in) just has a mini-DIN connector. uh oh.
which brings me back to here. does this mouse, despite the connector difference, use the same protocol?
looks like it is essentially the same protocol as the version of the mouse (type 4?) designed for the SPARCstation. the output is open collector, inverted async serial, 5 byte.
time to build an adapter. the connector is RJ11 (technically 6P4C) but it has these pins sticking out, presumably so you can't plug it into a phone jack.
four months later 
i made the Video Snake Oil board that can adapt 13W3 (any type!) to VGA. you just wire up the little pads to whatever your machine needs.
i made the Video Snake Oil board that can adapt 13W3 (any type!) to VGA. you just wire up the little pads to whatever your machine needs.
MUSE Bi-Vision@tubetime This inspires me - I have a VAXStation that uses a 3W3 video output (basically 13W3 without the digital pins) and it's impossible to find cables for it, but there are connectors for it around
Do you do any termination or anything active on the board? I've made an RGB port adapter before and got pretty bad ringing, but it could definitely just be the monitor I used since I had no other way of testing.