Hi,
On Thu, Oct 28, 2021 at 05:00:26PM -0400, Ethan Dicks via cctalk wrote:
  On Thu, Oct 28, 2021 at 10:00 AM Alan Perry <aperry
at snowmoose.com> wrote:
  Aside from the posts on the side of the
connector, what is unique about the cable and connector? What?s the deal with those posts?
Aside from them, it looks like a 6P4C with only three leads connected. 
 AFAIK, the posts are there so you don't plug your mouse into a phone
 jack or a modem port.  There are cutouts on the back of the Sun3
 keyboard to admit that connector.
 One could almost certainly start with a 6P4C cable and fix up the
 mouse end and re-use a Sun4 mouse, but for show/display purposes, it
 would be clearly a substitute. 
I am using a MiniDIN-8(F) to 6P4C (without those posts) cable I made to
connect a type 4 mouse to my type 3 keyboard.  Works perfectly.  I think
I found the pinouts for type 3 and type 4 mice in the SUN Hardware
Reference?  If anyone has trouble figuring it out I can measure the
connections on my adapter and post them.
Cheers,
--
Malte Dehling
<mdehling at gmail.com>