You might find the paper which Chuck Cranor did at:
http://www.ccrc.wustl.edu/pub/chuck/psgz/bsdatm.ps.gz
which describes how to configure PVC using his mods.
I wrote a driver for Efficient 25MHz card with the lanai chip set and
was able to configure the routing as described in the previous URL.
This was on a 1.3.3 and 1.4 system.
This does not use pvcsif to my knowlege.
johnh...

On Thu, 28 Oct 1999, Herb Peyerl wrote:

> itojun@iijlab.net  wrote:
>  > 	I added some ATM PVC pseudo device code as well as IPv6 code into it,
>  > 	basically from ALTQ distribution (www.csl.sony.co.jp/person/kjc).
>  > 	I heard that there were some configuration changes
>  > 	(previously we used route(8) to setup PVC, but now we need pvcsif(8)).
> 
> We tried all the combinations of pvcsif and route and whatever. Couldn't get it
> to work.  It doesn't even work in 1.4 which is Pre-IPV6 changes...
> 
>