From owner-freebsd-hackers Mon Oct 6 23:39:58 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id XAA01781 for hackers-outgoing; Mon, 6 Oct 1997 23:39:58 -0700 (PDT) (envelope-from owner-freebsd-hackers) Received: from proxy3.ba.best.com (root@proxy3.ba.best.com [206.184.139.14]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id XAA01774 for ; Mon, 6 Oct 1997 23:39:56 -0700 (PDT) (envelope-from mdean@shellx.best.com) Received: from shellx.best.com (shellx.best.com [206.86.0.11]) by proxy3.ba.best.com (8.8.7/8.8.BEST) with ESMTP id XAA02967; Mon, 6 Oct 1997 23:39:18 -0700 (PDT) Received: from localhost (mdean@localhost) by shellx.best.com (8.8.6/8.8.3) with SMTP id XAA02792; Mon, 6 Oct 1997 23:39:17 -0700 (PDT) Date: Mon, 6 Oct 1997 23:39:17 -0700 (PDT) From: mdean To: Peter Dufault cc: hackers@freebsd.org Subject: Re: A world of unexplored pain. In-Reply-To: <199710061908.PAA12422@hda.hda.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk By the way for those of you who might be wondering: Take a look at http://www.rtmx.com, from what a gather this is an excellent product, unfortunately it comes at a price: $3995, a bit too pricey for me. Those are just posix.1b extensions and tuning on the openbsd tree, and the developer I talked to said that there is good chance they may release them publicly in the near furture because of some kind of contract arangement I didn't quite understand. > > > > me to use some dedicated controller board) if that was all I wanted... > > I did something like this in 386bsd days for a combustion experiment. > > on the A-D board to watch for lost ticks by setting it for something > like (N + fudge) times the tick interval and verifying it wasn't > pending when I got to the control. So are you saying you were running at an interrupt frequency of 10000 Hz (gee wiz ma I only want 1000hz)? So what did you see in the way of lost tick statistics? > We could telnet into the box, display status in a remote xterm, > etc, without screwing things up. It was a hack but worked well. One word: BadASS! Many people would have me believe this can't be done adequately with freebsd. You wrote labpc.c (I've been using it as a reference, I have one of those boards I want to connect the stepper motor drivers to.) excellent piece of code, there are a lot of features of the labpc I've never even ventured into. I particularily like its ability to post an interrupt on completion of forming an AtoD value. Unfortunately that doesn't work right once youv'e connected it to an external multiplexer system, because there is no good way to tell that the Analog Value has stabilised, you just need to _WAIT_ a prescribed amount of time. This is precisely why I wan't to put scans inside a 1000hz interrupt routine. > Things have grown a lot since then. Grown to what?