Re: linuxWin-modems don't work with Linux Re: uart 16550AN

Mike Black (mblack@csihq.com)
Sat, 10 Jan 1998 07:02:01 -0500


> From: David Fries <dfries@mail.win.org>
> Date: Fri, 9 Jan 1998 02:53:37 -0600
> Subject: Win-modems don't work with Linux Re: uart 16550AN
>
> - --JI16pVnmMjqg7Yu+
> Content-Type: text/plain; charset=us-ascii
>
> On Fri, Jan 09, 1998 at 03:24:27AM -0500, Richard M. Heiberger wrote:
> > This chip is in the "Telepath for Windows with x2" modem that is
included in
> > my new Gateway 300 MHz machine. I originally installed 2.0.25 from the
> > Linux Universe CD-ROM. linux refuses to acknowledge the device. it
claims
> > an "unknown" chip. I downloaded 2.1.78 and am looking at the source
code.
> > The string "16550AN" is not there. I assume therefore that this
version will
> > also not be able to talk to my hardware.
I used to have a PNP modem and found (at the time) that I had to boot
Windows first to get it set up and then warmboot to Linux. 16550AN has
been around for a LONG time so I don't think that's your problem.

> >
> > I have a second, probably related problem. Com1 has a 16550A chip.
> > I can use it to configure a direct connection ppp link to another
machine.
> > linux refuses to recognize an external modem when I place it on that
line.
In most computers COM1 and COM2 are wired for DCE/DTE respectively -- in
other words, you need a null-modem cable to connect to COM1.

> You have one of those things called a "win-modem." They fall in the
> same catagory as win-*, or commonly refered to is a windows only
> (inseart computer device name). They all have one thing in common,
> they leave off hardware and expect your brand new (and I'm sure
> expensive) processor to make up for it, just to save them selves a few
> $$. To interperate, your computer is posessing performace deteriating
> devices.
>
'scuse me??? Since when did manufacturers get together on a naming
standard??? A WinModem does NOT take any system processing -- in fact it
performs BETTER than an external modem as you eliminate a dual-RS232
conversion. It is cheaper to make an internal rather than external
modem...but a USR WinModem AIN'T CHEAP! What you're thinking of is the
printers -- they DID move a lot of the processing onto your computer (but
note that there is no analog data involved, just digital conversion).

> To put it another way, that big expensive pice of computer that you
> thought you were getting the highest quailty components and probably
> wanted something up to date or advanced while what you really got is
> is a computer with the cheapest USRobotics modem you can find, which
> has the most problems of all USRobotics modems (which I would
> personally inseart that I have two of their better USRobotics 56k
> modems that on BOTH of them I must disable compression or they
> hang/reset(drop connection) or go a 500bytes/sec eventually, trust me
> I have had 5 of them they aren't any good.) Back to what I was
> saying, you got the cheapest USRobotics modems, that has the most
> problems, that not even under windows can you use it in a dos program,
> because the manufacturer left off the prom, flash hardware, and
> related chips to move it to the system memory so it only works with
> windows.
>
I've been using USR exclusively for 5 years -- I give them an A+ for
reliability and support. There was a software bug in the first 33.6 modems
that caused degrading performance but USR provided a FREE PROM replacement!
The WinModem now has flash memory so you can upgrade without opening the
case. This also reduces the cost of manufacturing.

> I hear some manufacturers actually moved the DSP (ditital signal
> processor) functions from the modem to the computer, that is just
> something I heard, USRobotics didn't do that, just the rom code that
> tells the dsp what to do.
>
USR did remove the ROM, but it ain't on your computer! They put in flash
memory instead. The DSP code is still on the board. And (in case you
didn't know) you CANNOT move a DSP "onto" your computer -- there ain't no
analog input line to play with (other than the game port but we won't count
that :-).