Messages in this thread | | | Date | Thu, 27 Mar 2008 17:00:36 -0400 | Subject | Re: Real time USB2Serial devices and behaivor | From | (Lennart Sorensen) |
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On Thu, Mar 27, 2008 at 12:48:40PM -0700, David Brownell wrote: > I happened across this the other day, and saved the URL since > the price was relatively sane ... $15 vs the $60 I saw at > another site, although ISTR Fry's used to have them at $5: > > http://www.wrighthobbies.net/catalog/index.php?cPath=47 > > Yeah, I know. "It's getting very hard to find real PCI slots > any more." :(
Well digi (www.digi.com) makes some nice PCI serial cards, that work with the jsm driver. Not sure how many models are supported, but certainly I have used the 2 port card with DE-9 connectors.
A little bit of patching will make the jsm driver run any exar 17[CD]15[248] based card, like the ones we use on the routers I work on. The digi cards use a rebranded exar chip with a different PCI id. Much better than using the 8250 driver to run the exar's in PCI 16550A mode, although it does work.
They have PCIe cards too although I have no idea if they use the same interface or not (it would make sense to do so on the part of exar though).
> It seems like some companies (notably *cough* Intel) are > on a little jihad to get rid of serial ports... > > I'd think that in a controlled environment (fixed set of > USB connections) USB should be able to meet fairly chosen > "real time" latency ceilings. The stack probably needs a > few semantic updates to make it happen -- e.g. URB completions > are issued in_irq() -- but it shouldn't be insurmountable.
-- Len Sorensen
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