Subject: Re: Pinouts of VAXstations
To: None <port-vax@netbsd.org>
From: Thor Lancelot Simon <tls@panix.com>
List: port-vax
Date: 09/20/1998 22:45:48
On Fri, Sep 18, 1998 at 03:42:58PM -0700, Adam Fritzler wrote:
> 
> 
> >AUDIO INTERFACE: the best thing ever seen... The audio controller is a
> >AM79C30, a chip originally designed as DSL-controller for
> >ISDN-telecommunications. Maybe i'll try to "abuse" the chip for this
> >sometimes. When the 4000 VLC is supported by NetBSD.
> >OK, the pinout is as follows: (RJ-11 or so connector, the same as on
> >modems, counted from left to right when you look in the connector, pins
> >at the upperside)
> 
> Sounds like wht the DECstations did.  The ioasic decstations had ISDN and
> sound, and I believe using the same chip.  

Did this actually ever work under Ultrix?

Reliably?

You need a pretty damned low interrupt latency to get a 79C30 to actually
be useful for ISDN, IIRC; it's totally dumb, so you have to run the link
layer protocol on the host CPU.  There are several different kinds of
Unix workstations of similar vintage to the ioasic DECstations which
had "ISDN" ports on them that stayed "temporarily" taped over pending
regulatory approval/existence of device driver software until the
day the very last machines rolled off the production line in the factory.

I'd be a little surprised to see this work on a VAX.