>Sounds like the SUN breakout boxes. Does the DEC have an input connector, too?
>In that case, my SUN box will probably be sacrificed. =)

Yes.  According to DEC3000-300 diagram;

     4 |||| 1      (RJ modular conn, lead side up)
    
        1       Audio in A
	2	Earphone interface 1 (audio out)
	3	Earphone interface 2 (audio out return)
	4	Audio input B (ground)

And the page states "this port is pin-compatible with a telephone
handset." I have a carled splitter widget and it has MIC terminal and
PHONE terminal on one end.

Audio/ISDN interface found in MAXINE and DEC3000 was designed to
compete to some models of SPARCstation.

Tohru Nishimura