From owner-freebsd-hardware Wed Mar 10 11:26:15 1999 Delivered-To: freebsd-hardware@freebsd.org Received: from palrel1.hp.com (palrel1.hp.com [156.153.255.242]) by hub.freebsd.org (Postfix) with ESMTP id 82CDE154D5 for ; Wed, 10 Mar 1999 11:25:18 -0800 (PST) (envelope-from darrylo@sr.hp.com) Received: from srmail.sr.hp.com (srmail.sr.hp.com [15.4.45.14]) by palrel1.hp.com (8.8.6/8.8.5tis) with ESMTP id LAA07455 for ; Wed, 10 Mar 1999 11:25:00 -0800 (PST) Received: from mina.sr.hp.com by srmail.sr.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA120163899; Wed, 10 Mar 1999 11:24:59 -0800 Received: from localhost (darrylo@mina.sr.hp.com [15.4.42.247]) by mina.sr.hp.com with ESMTP (8.8.6 (PHNE_14041)/8.7.3 TIS 5.0) id LAA13771 for ; Wed, 10 Mar 1999 11:24:59 -0800 (PST) Message-Id: <199903101924.LAA13771@mina.sr.hp.com> To: freebsd-hardware@FreeBSD.ORG Subject: Re: PCI WinModem Reply-To: Darryl Okahata In-Reply-To: Your message of "Wed, 10 Mar 1999 13:45:16 EST." Mime-Version: 1.0 (generated by tm-edit 1.1.1.1) Content-Type: text/plain; charset=US-ASCII Date: Wed, 10 Mar 1999 11:24:58 -0800 From: Darryl Okahata Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Chuck Robey wrote: > The simple minded thing just offloads all > the signal processing of a modem onto your processor, which means it > can't do anything else useful while the modem's going. That isn't > smart, that's idiotic, especially seeing as the price of *real* modems > isn't all that high, comparatively speaking. I'm wondering: is this really how winmodems work? I've always thought that this is how winmodems worked, but, after thinking about it, they don't have to work this way. The DSP could be done by a cheap IC (and often is, on non-winmodems, at least). That leaves the "com port/external modem emulation hardware", which could be completely dropped without affecting performance. In a non-winmodem modem, you've got a processor that handles I/O from the PC and the DSP -- something like: +------------+ +-----+ +-----------+ +----+ | phone line |-->| DSP |-->| processor |-->| PC | +------------+ +-----+ +-----------+ +----+ Now, for an internal modem, this processor is really superfluous. One of its functions is to handle the various "AT" commands, but using the PC for this is a fair trade-off for many people (as long as there's no possibility of data loss with heavy loads). I like offloading tasks from the CPU, and so I'd never buy a winmodem, but winmodems might be adequate for some people (iff the DSP functions were not done by the CPU). -- Darryl Okahata darrylo@sr.hp.com DISCLAIMER: this message is the author's personal opinion and does not constitute the support, opinion, or policy of Hewlett-Packard, or of the little green men that have been following him all day. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message