USB modem will not install


J

Joe Morris

Paul said:
The OS has a certain number of "USB Class" drivers, which
are standardized against the standards of USB.org. And that's
how a lot of stuff is supported, without usage of a separate
driver CD. However, it's still possible for a hardware
designer to design custom hardware, set the class to indicate
"Custom", in which case Windows should back off, until the
driver CD is used.
That's why many products have installation instructions telling you not to
connect the USB device to your computer until after you run its installation
program. USB drivers are selected in order of increasing general
applicability, first looking (simplified) for a match on class+model+rev,
then class+model, then class. Thus, if you have a USB memory stick that
doubles as a hand warmer [*] it will be default get the generic memory
device driver, but if you run its software installer first you'll get the
driver that also offers a thermostat.

Joe

[*] On the reference to a "hand-warmer" option: it's not a deliberate
feature with a device driver-provided thermostat...but the new 32 GB USB3
stick from Kingston (model "DT Ultimate") that's intended to support Windows
To Go on WIN8 does get quite toasty. Kingston's been made aware of the
problem and is reportedly working on a fix.
 
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Z

Zaphod Beeblebrox

You don't need a driver to communicate to a serial port. And a modem
connected to a serial port doesn't need a driver either.

They do need drivers, that is if you want them to have full
functionality. Different modems had varying implementations and
extensions of the AT command set, and choosing the wrong one could
reduce the connect speed or limit the modem's ability to actually work
properly.
It doesn't matter if the serial modem is plug or play or not. If it
isn't, you just have to tell the BIOS what settings to use and Windows
will play along. All of the above is true except if the modem is a Winmodem.
I don't think it is even possible for there to be a serial Winmodem.
Their functionality relies on offloading functionality to the CPU,
which requires a tighter coupling than the serial port provides.

--
Zaphod

"So [Trillian], two heads is what does it for a girl?"
"...Anything else [Zaphod]'s got two of?"
- Arthur Dent
 
P

Paul

Zaphod said:
They do need drivers, that is if you want them to have full
functionality. Different modems had varying implementations and
extensions of the AT command set, and choosing the wrong one could
reduce the connect speed or limit the modem's ability to actually work
properly.


I don't think it is even possible for there to be a serial Winmodem.
Their functionality relies on offloading functionality to the CPU,
which requires a tighter coupling than the serial port provides.
There's a USB dialup modem here, claiming to have onboard DSP.
It's more than twice the price of the other soft-modems. It
was the only one I could find. All the rest look like soft-modems,
in that form factor.

http://www.newegg.com/Product/Product.aspx?Item=N82E16825115042

That was about as hard to find, as one of those dialup
modems with an Ethernet port on it :)

In a quick search, I can see Conexant makes something like that.
Page 2 shows the main chip has its own DSP.

http://www.conexant.com/servlets/DownloadServlet/PBR-201492-001.pdf?docid=1494&revid=1

"Because it is a hardware modem, it can be easily
adopted in non-x86 CPU and non-Windows OS based systems.
The modem will operate with any system that has a
USB CDC (Communication Device Class) driver."

Paul
 
D

DanS

I don't see this too often, as it depends on the driver. And I am pretty
sure the drivers that has to reinstall in an USB port it never used
before are also the same drivers can only work with one such device per
machine.

For example, I have like a dozen USB to RS-232 adapters. They are all
the same and worthless without a driver. And I bought a dozen of these
thinking that I could have any many COM ports as I would like on a
machine. While they work fine one per machine. They don't work if you
have two or more per machine.
You're probably talking for laptop use...FWIW, for desktop use, I've got
3 of these in one machine providing a total of 6 serial ports.

http://www.newegg.com/Product/Product.aspx?Item=N82E16815166004

(Albeit an older machine, because I don't believe many PCs come with 3 PCI
slots any longer.)
 
D

DanS

Don't be sad. I'd call it a behavior, not a problem, and as behaviors
go, this one is not particularly annoying.
Yes it is a behavior, and typically not a problem, but it still is
particularly annoying to me. Everyone's got something that just gets
under their skin for no real reason.
 
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P

Paul

BillW50 said:
I don't see this too often, as it depends on the driver. And I am pretty
sure the drivers that has to reinstall in an USB port it never used
before are also the same drivers can only work with one such device per
machine.

For example, I have like a dozen USB to RS-232 adapters. They are all
the same and worthless without a driver. And I bought a dozen of these
thinking that I could have any many COM ports as I would like on a
machine. While they work fine one per machine. They don't work if you
have two or more per machine.
Sure they do. Here are a couple FTDI chip based USB to serial ports,
running the VCP driver. Show as COM3 and COM4. If they get unplugged
and plugged into new USB connectors, they're supposed to preserve
their COM3 and COM4 labels. COM3 connects to my UPS, for early
shutdown notification. COM4 connects to a USR Modem or any
other ongoing serial experiment (like the serial port to the
Linux box plus putty, a year ago).

http://img17.imageshack.us/img17/7359/ftdivcp.gif

I don't know how many underlying chips there are for
this, but those are pretty popular. I got those at
a local computer store, with different external branding
on each one, but the shop staff assured me they were the
same PCB inside. They have the "flashing red LEDs"
as a distinguishing feature. Useful and silly, at
the same time. The red light is annoying, until you
actually need the indicators.

Model number UMC-201, similar to this. My computer store
is bankrupt, so I can't actually link to them any more.
So this will have to do. The cabling on mine is black in
color, while the cables on these are the "sparkly transparent"
style cables. Just about anyone can pretend they're
manufacturing them.

http://www.l-com.com/item.aspx?id=9919

Paul
 
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