Path: utzoo!mnetor!uunet!husc6!bloom-beacon!mit-eddie!bbn!rochester!ur-tut!sunybcs!moogvax!terry
From: terry@moogvax.UUCP (Terry Westley)
Newsgroups: comp.os.vms
Subject: Need help with VAX/VMS DMA data transfers
Message-ID: <713@moogvax.UUCP>
Date: 18 Mar 88 14:09:53 GMT
Distribution: na
Organization: Moog Inc. Electronics & Systems Division, Orchard Park NY
Lines: 29
Keywords: DMA, data acquisition, device driver

H E L P  ! ! !

I am using a MicroVAX II with VMS for a real-time application in which
I need to perform some analog data acquisition in which other
processing is so heavy that I don't want to use a device driver.
I'd like to simply access the registers of my board (a Data Translation
3362) and DMA the acquired data into VAX memory.

I have been able to successfully perform data acquisition with a
programmed I/O technique, but I have discovered that DMA transfers
require a lot of knowledge about map registers and buffered data paths
that I do not possess.

Does anyone have a snippet of code in any language that shows how I can
set up and perform DMA transfers from any board.  High-level language
(C specifically) would be perferred, but "beggars can't be choosers."
I have a DEC manual on how to write device drivers, but am not able to
make heads or tails of it.

I would greatly appreciate receiving e-mail from anyone who could help
me out.  

Thank you.

-- 
  Terry Westley         
  Moog, Inc. (no, not the synthesizer company)
  East Aurora, NY  14052-0018
  {boulder,decvax,rocksanne,rutgers,ames}!sunybcs!moogvax!terry