Date: Fri, 23 Oct 1998 08:31:43 +0930 From: Greg Lehey <grog@lemis.com> To: Nick Hibma <nick.hibma@jrc.it>, Luigi Rizzo <luigi@labinfo.iet.unipi.it> Cc: sos@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: USB (was: multi-user: multiple consoles in FreeBSD) Message-ID: <19981023083143.C28824@freebie.lemis.com> In-Reply-To: <Pine.GSO.3.95q.981022120028.17573L-100000@elect8>; from Nick Hibma on Thu, Oct 22, 1998 at 12:04:50PM %2B0200 References: <199810220803.JAA11764@labinfo.iet.unipi.it> <Pine.GSO.3.95q.981022120028.17573L-100000@elect8>
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On Thursday, 22 October 1998 at 12:04:50 +0200, Nick Hibma wrote:
>> Speaking of USB: i have read that bus throughput with a single node is
>> reported at about 750KB/s, whereas with multiple nodes bus throughput
>> falls down very rapidly (because of arbitration etc ?) to 250KB or so.
>
>> So i would not want a HD on it!
>
> At max of 1mb/s a second (I can't remember the exact theoretical
> maximum, but it should be more than 750Kb/s) you dont' want to have more
> than a floppy attached to that port.
I've just bought an Epson Stylus 740, which comes with both parallel
and USB interfaces. One of the two CDs that come with it include some
silly "documentation" (not a word anywhere of the control codes it
uses), but it does describe some aspects of the USB interface. It
states that it supports a bit rate of 12 Mb/s ("full speed device").
I think this is possibly acceptable for a printer; it's certainly a
lot more than a parallel port can handle. It also states that it uses
NRZI data encording [sic], and that the driver requires 10 MB of disk
space. I wonder how big a kernel would be if they supplied it.
Greg
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