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Re: Ethernet collision with modem?
Apropos COMs and shared interrupts:
Linux can handle a shared interrupt if it is handled properly in hardware.
The problem is, that ISA cards cannot properly handle a shared interrupt
unless both sources are on the same card and some special tricker (an OR
gate) is used by the manufacturer.
It follows that COM ports and other devices CAN share interruptasIFF:
1.They are both on anISA card and the OR gate is there or
2.They are both on a PCI card or
3.If they are in the chipset.
3. is only true for some chipsets. This means that you can set COM1 and
COM3 or COM2 and COM4 for onboard chipsets together (for some at least).
The only way to find ou, is to try.
On Mon, 24 Nov 1997, Eli Marmor wrote:
> Doron Shikmoni wrote:
> >
> > >I have installed Ethernet Gold2000 card (NE2000 compatible) into my PC
> > >and my modem stopped working ... After removing it it came to work again.
> > >The modem was online but it couldn't dial...
> > >How can it make a collision? my modem is using /dev/cua1 (external) but I
> > >didn't configured the /dev/ethX yet. Is it possible? There no jumpers on
> > >the card ???
> >
> > Sounds like an IRQ conflict. Check whether the Eth adapter uses
> > (or defaults) to IRQ3.
> >
> > Doron Shikmoni
>
> BTW: Is it possible to use more than 2 COMs concurrently? I spent
> 3 hours on that, today. COM1 is used by the mouse, and COM2 by the
> modem. I want to be the "console" of a router, so I configured the
> unused port to be COM4, but it seems tohave collision with IRQs.
> One of about 10-20 characters is got, and the others lost. I did the
> checks with minicom, but there must be something simpler for direct
> communication, is there?
> (I didn't forget to disable the agetty of the tty).
>
>
> P.S. Stas! If anybody wants you to charge the *real* cost, you
> should agree... by doubling the price!
> I ordered 2 weeks ago the freeware OS, NetBSD, by FedEx, from
> Infomagic. This "free" CD cost $35, +$37 for shipping, +81 NIS for
> Flying Cargo (like in Sdom-VaAmora: this CD "layed" 80 hours in their
> store in Lod, because Kfar-Saba was too far for them from Lod. The
> way from Arizona to Lod took only 36 hours! So I had to pay for their
> laziness!). Total cost was 340 NIS. Stas, don't be shamed, take more!
> We are all (or at least me) in the back of you!
>
> --
> Eli Marmor
> marmor@elmar.co.il
> 09-7661020
>
Peter Lorand Peres
------------------
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