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Conference nlfdc::linux-users

Title:Linux, the Free Operating System
Notice:New here? Sign in on topic 2
Moderator:EST::DEEGAN
Created:Fri Feb 11 1994
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:609
Total number of notes:2862

595.0. "I/O Error when trying to access a modem on a serial port....." by HANNAH::SMITH (Michael J. Smith: MRO1-2/J25) Tue Apr 29 1997 17:02

I have been trying to use my Supra 288i modem under Linux with no
luck. The modem works fine under Windows95 but I cannot get to
square one with Linux.

Under windoze the modem is on COM3 and works just fine.

Checking out the /dev/cua* and /dev/ttyS* devices show that
they are correct with the majors, minors, etc.

I have set up /dev/cua2 and /dev/modem up using setserial and
then when I try and access the modem I always get some sort of
"I/O error" message.

Using stty results in a message like this...

	stty: standard input: I/O error

Using cat get this message...

	cat: - : I/O error

Using seyon (a communications) package delivers these messages...

	seyon - Error: ioctl-ioflush: I/O error

also ioctl-get, ioctl-get & character-read I/O error show too.

I have tried setting different IRQ's on /dev/cua2 an always get
the I/O error message. All the documents I have, including the
Serial HOWTO do not address this basic error. There must be some 
basic configuration thing I am missing here but I am clueless at
this point.

Anybody got an idea of what the problem is?

Thanks,
Mike

 

 
T.RTitleUserPersonal
Name
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595.1QuestionsNEWVAX::PAVLICEKLinux: the PC O/S that isn't PCTue Apr 29 1997 20:0312
    Does your modem use a non-standard IRQ or address under Windows95?
    
    What is the syntax of the setserial command that your are using?
    
    Try a "setserial -a /dev/cua2" and post the results here.
    
    Does the UART from the command above match whatever Windows95 thinks
    the UART is (from MSD or whatever the W95 equivalent is these days)?
    
    The Supra isn't a "Windows modem", is it?
    
    -- Russ
595.2more info....HANNAH::SMITHMichael J. Smith: MRO1-2/J25Wed Apr 30 1997 16:5535
The modem config using Windows95 looks like this...

	Supra 288i SP
	Interrupt 5
	Port 3E8
	NS 16550AN - UART
	115k Baud highest

I did a 

	setserial /dev/cua2 irq 5 uart 16550A

And a setserial -a /dev/cua2 produces...

	/dev.cua2, Line 2, UART: 16550A, Port: 0x03e8, IRQ: 5
	Baud_base: 115200, close-delay: 50, divisor: 0
	Flags: spd_normal, skip_test


Meanwhile I tried to use the web to get the specs on the supra 
modem in order to find out if it is a "windows" modem (shudder) 
and I stumbled over some info in

	http://www.redhat.com/support/mailing-lists
	    /archives/redhat-list/1996-November-1/0585.html

Which pointed off to

	http://www.redhat.com/linux-info/pnp/

I'm going check that all out next. Seems somebody has a magic
little utility that needs to get run before setserial runs...

Thanks,
Mike
595.3Modem working now....HANNAH::SMITHMichael J. Smith: MRO1-2/J25Fri May 02 1997 17:0714
I got the PNP (Plug and Play) software via the web address in the 
previous note and installed it on my Linix RedHat 3.0.3 system.

Seems if you have some PNP devices then you must PNP'em (Poke and 
Prod) before they will PNP.

The instructions that are in the kit are sufficent, RTFM.

You use a utility to dump out the confgurations for your
PNP devices into a file. You edit the file by removing any
devices and configurations you don't want. Next you run
a setup utility that uses your config file to PNP your
device(s).  At this point your system can now operate on
the device.