[plug] pci modem (and serial and parallel ports)

[Leon Brooks]

Matt Kemner wrote:
> On 3 Aug 2000, Joshua Pierre wrote:
>> First you check it isnt a winmodem to save you bothering =)

> I may be wrong here,

A first! A first! My first Matt-is-wrong post! (-:

> but I've heard that if it's a PCI modem it's a
> winmodem - because traditionally serial ports hang off the ISA bus, and
> even with Pentium mainboards (and newer) even though the ports are
> on-board, they are physically connected to the ISA bus - and there is no
> standard (yet) for serial ports on the PCI bus, so Linux does not know
> where to look.

A WinModem, or "software modem" has at least part of the modem work done
by the CPU. This can mean "a little bit" like doing the management
things (see rings, lift hook, send codes to DTMF chip etc) or "Host
Based" in which the actual bulk signal-processing arithmetic is done by
the CPU. Bletch. This normally uses the horsepower equivelent of a
Pentium 90 under Windows, and doesn't work very reliably. Hence the
term, _Win_Modem. (-:

Linux can drive practically any serial port that ever lived. 2.4.0pre*
does it natively, and you can upgrade 2.2.*'s serial driver to match. If
the driver doesn't support it yet, you can specify parameters, and/or
send the author a pcitools dump of the greeblie and it will appear in
the following kernel version. This means that Linux can drive PCI
hardware modems. There is also shaky Linux support in the form of
patches for at least one Host Based modem, and a very few
some-assembly-required software modems for 2.3.* and 2.4.* kernels.

This I discovered while getting some brand-x PCI serial ports to work on
a Linux box. I believe the same story can be told for PCI parallel
ports.

-- 
Other than that, Mrs Lincoln, how was the play?