probably the best all around board for async ports is the DHV11, M3104. 
it give you 8 lines capable up up to 38400 each, and has been supported 
by BSD since 1984..  :-)

theyre pretty easy to find, though the cab kits arent so common anymore. 
You can wire conenctors yourself. there are two 40pin berg connectors on the
board, which fan out to 4 rs232 lines each. the pinouts are commonly 
findable, or ill post the pinout next time im near my manuals. 

happy hacking,
isildur

On Thu, 25 Jan 2001, M J Dowden wrote:

>      I would like to connect a modem to my VAX 4000-300, but it has 
> neither a modem port nor a Q-bus comm card. I'd like to find out what 
> type of Q-bus card will work with this model, which is running NetBSD 
> 1.5 (the hardware page at netbsd.org wasn't clear on that point). I'd 
> also appreciate any tips on where I might find such an unusual and 
> antique part.
> 
>      Best regards,
>      Mike Dowden
>