I hate to disappoint you, but it won't do anything like the acquisition 
time for audio.  Isolated in this context means that you can read 
millivolts on top of a high voltage common mode waveform. The a/d is 
connected via a flying capacitor which charges off the signal and is then 
flipped over to the a/d using a reed relay!    I have been thinking about 
monitoring the 117 volts in my building and graphing it to prove to the 
power company that it is off-spec, hence the need for the driver.

These interfaces were pretty rare, I got this in an auction at the Canadian 
Data Translation disti when they got out of the DEC business. It listed for 
about $2000 US I htink.

As far as the MP3s go, some of my students did this with a 2MHz Motorola 
68HC11 so it should be possible with a VAX.

regards
Nigel Johnson


At 11:49 02-10-25 -0700, Brian Chase wrote:
>On Fri, 25 Oct 2002, Nigel Johnson wrote:
>
> > btw, I am happily chugging along on with NetBSD on my MicroVax IIs.  One of
> > them has a Data Translation DT2765 millivolt isolated a/d that I am dying
> > to use to measure dome kind of power line stuff, but anybody who suggests
> > an experiment also has to come up with a driver!
>
>Oooh.  One project I always thought would be interesting is using A/D
>and D/A Qbus modules to build a sound card for a VAX.  I doubt a
>MicroVAX-II would have the VUPs to decode mp3s on the fly, but I'd
>imagine it'd be fine for low-fidelity uncompressed audio.  I'm sure some
>of the newer VAX 4000 series would be well suited for the task.
>
>The major obstacle being the scarcity of such modules.  I only know of
>their existence from Megan Gentry's _Field Guide to Qbus and Unibus
>Modules_; I've never seen them "in the wild."
>
>-brian.