Path: utzoo!attcan!uunet!lll-winken!decwrl!ucbvax!UMIX.CC.UMICH.EDU!krowitz%richter
From: krowitz%richter@UMIX.CC.UMICH.EDU (David Krowitz)
Newsgroups: comp.sys.apollo
Subject: Re:  Recommendations for GPIB interface
Message-ID: <9003231447.AA09765@richter.mit.edu>
Date: 23 Mar 90 14:47:18 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 25

I've used a National Instruments PC2 (or 2A?) card to interface a
color page scanner to a DN3000 and DN3500. The GPIO device drive
library they provided (written in C) compiled and linked with no
problems and seemed to work for my purposes. They do not supply an
IOS manager (ie. Unix or AEGIS streams). It would be almost impossible
to write one as every GPIB device I have come across requires a
different sequence of GPIB commands. I did use DMA transfers with EOI
and managed to get on the order of 200,000 bytes/sec when reading
data from the scanner. I can't really address the other issues, as
I didn't get that deep into their GPIO device driver code. I just
stuck with using the interface routines in the library they provided.
One nice feature was that they provided a little interactive program
which I could use to issue GPIB commands from the keyboard. It was
not very fancy, but it allowed me to figure out the correct 
handshaking sequence for the various scanner models without having
to write code based on a mere guess as to what the scanner manufacturer's
manual *really* meant to say.


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
krowitz%richter.mit.edu@eddie.mit.edu
krowitz%richter.mit.edu@mitvma.bitnet
(in order of decreasing preference)