9-pin
Hello Nicholas,                             Port A            Terminal
                                            ~~~~~~            ~~~~~~~~
The serial pinout that I found for the      TXD  2 ----\/----  3 TXD
SPARCstation 10 seems to lack DSR and       RXD  3 <---/\--->  2 RXD
RI pins for serial port B.  RI probably
doesn't matter if your software looks       RTS  4 ----\/----  7 RTS
for "RING" from the modem as data.  I       CTS  5 <---/\--->  8 CTS
don't know how NetBSD handles DSR if it
is really missing.  Perhaps it always       DTR 20 ----\/----  4 DTR
looks asserted.                             DSR  6 <-+-/\-+->  6 DSR
                                            DCD  8 <-'    `->  1 DCD
I hope this helps.
  - Andy Ball.                              SG   7 ----------  5 SG


                                                              25-pin
                                            Port B            Modem
                                            ~~~~~~            ~~~~~~
                                            TXD 14 --------->  2 TXD
                                            RXD 16 <---------  3 RXD

                                            RTS 19 --------->  4 RTS
                                            CTS 13 <---------  5 CTS

                                            DTR 11 ---------> 20 DTR
                                            DCD 12 <---------  8 DCD

                                            SG   7 ----------  7 SG