Subject: Re: z50 Internal Modem Device Name
To: Benjamin David Sexson <bensexson@earthlink.net>
From: Jim Fleming <jim.fleming@moblcode.com>
List: port-hpcmips
Date: 11/20/2002 11:57:47
----- Original Message -----
From: "Benjamin David Sexson" <bensexson@earthlink.net>
To: "Port-Hpcmips" <port-hpcmips@netbsd.org>
Sent: Tuesday, November 19, 2002 8:49 PM
Subject: RE: z50 Internal Modem Device Name


> The modem uses a Rockwell RP336LD Modem Data Pump (I don't really know
what
> this means?).  I am guessing that this sends the data to the processor
which
> then emulates a UART.  So I guess it wouldn't be that easy to port a
> linmodem to NetBSD.  Anybody have any idea how to start making a driver?
>
> Thanks Ben
>
> > -----Original Message-----
> > From: Thomas Miller [mailto:thomas.miller@lycos.com]
> > Sent: Thursday, November 14, 2002 6:29 PM
> > To: Benjamin David Sexson
> > Subject: RE: z50 Internal Modem Device Name
> >
> >
> > Hi,
> >
> > I am not certain I understand all this completely correctly, but . . .
> >
> > One of the critical hardware items missing from a Winmodem is
> > something called a UART.  Winmodems work by shifting the
> > processing work from the UART to the central prucessing unit.
> >
> > When I saw ns6550a (or whatever) in the dmesg, I assumed that
> > this meant the modem was a "hardware" modem, because ns6550a is
> > the designation of a type of UART.
> >
> > Actually, however, it appears from the comments on the list the
> > NEC 4121 processor in the z50 has UART emulation built into the
> > hardware of the processor.  Therefore, there needs to be a
> > special driver written for this particular NEC chip so that the
> > NetBSD kernel can access the UART at a different address than
> > where the UART would be if the UART were a regular UART in a
> > "hardware" modem.  This driver would be different from the
> > Winmodem type driver because the Winmodem driver would provide
> > software UART emulation rather than simply accessing the VR4121
> > hardware UART at a different location than usual.
> >
> > Again I am not sure all this is correct, but hope it helps.
> > Until someone gets around to writing the driver, we have to use
> > pcmcia or external modems in our z50s.  My z50 works fine with
> > both types; you can pick one up for ten or twenty buscks on ebay.
> >
> > Kindest regards,
> >
> > Tom
> >
> > thomas.miller@lycos.com
> > (Thomas Miller)
> > (617) 248-8900
> >
> > Any following text may include a message which was added by Lycos
> > and which is not a communication from me.
> >
> >
> >
> >
> >
> > On Wed, 13 Nov 2002 20:38:10
> >  Benjamin David Sexson wrote:
> > >Is this one of the linmodem drivers? one of the LT drivers and how do
you
> > >get it to work?
> > >
> > >> -----Original Message-----
> > >> From: port-hpcmips-owner@netbsd.org
> > >> [mailto:port-hpcmips-owner@netbsd.org]On Behalf Of Thomas Miller
> > >> Sent: Tuesday, November 12, 2002 7:51 PM
> > >> To: M. Warner Losh
> > >> Cc: port-hpcmips@netbsd.org
> > >> Subject: Re: z50 Internal Modem Device Name
> > >>
> > >>
> > >> On Tue, 12 Nov 2002 17:40:32
> > >>  M. Warner Losh wrote:
> > >> >
> > >> >The Vr4121 and Vr4111 docs have enough information to >write a
> > >> driver for this modem (if they use the one that's >mostly built
> > >> into the Vr41xx CPU), but no one has done so.
> > >>
> > >> Greg's kernel finds the modem:
> > >>
> > >> z50# dmesg | grep com0
> > >> com0 at vr4102ip0 addr 0x0c000000-0007:
> > >> ns16550a, working fifo
> > >>
> > >> When I saw the ns16550a I figured it ought to work.
> > >>
> > >>
> > >> __________________________________________________________
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> > >
> > >
> > >
> >
> >
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>
>