Date: Fri, 31 Aug 2007 09:46:52 -0300 From: Ricardo Nabinger Sanchez <rnsanchez@wait4.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: arch@freebsd.org Subject: Re: Proof of concept: soundcard as console device Message-ID: <20070831094652.0cf1f3a8.rnsanchez@wait4.org> In-Reply-To: <8412.1188553371@critter.freebsd.dk> References: <8412.1188553371@critter.freebsd.dk>
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On Fri, 31 Aug 2007 09:42:51 +0000 Poul-Henning Kamp <phk@phk.freebsd.dk> wrote: > What's left to do: >=20 > * optimize transmission schema. >=20 > This can be done with two computers, a jack-jack cable > and a bit of C-coding. >=20 > The difference in sample rate between the two machines > causes off-by-one errors. I don't know of a peak > detector which interpolates can resolve this, of if we need use > oversampling in the receiver. >=20 > The two pulses can have two different polarities each, > so we can transmit two bits just that way, this could > speed up transmission by a factor of four, if we can find a way > to synchronize properly. >=20 > The two stereo channels can be used independently, > offering a doubling in speed. Sounds like a synchronization pattern could be used here, like the one used for E1 channels (resync at every 512 bits), or any other scheme for plesiochronous channels. Or taking one channel to signal when data is ready. This is simply =FCber-cool. :) --=20 Ricardo Nabinger Sanchez rnsanchez@wait4.org Powered by FreeBSD "Left to themselves, things tend to go from bad to worse."
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