[comp.unix.questions] modem problems

TSARS@uga.cc.uga.edu ( mark porporino) (07/16/90)

I am running SCO Xenix 386 2.3.2c and have a very annoying problem with the
dial in line:  I see the message "Serial: ERROR: Garbage or loose cable on
/dev/tty1A, port shut down" on my console when a call comes in to my external
2400bps ZOOM modem.  I am using the Hayes command "ATE0Q1" along with others I
thought might help.  To complicate matters more, sometimes a caller is able to
dial in with no problems (usually after a local dial out).  I tried both the
hayes12 and 2400 dialers.

I now believe that this problem is due to poorly written modem command set.
If I but a new modem today, and this problem is solved, I'll never know exactly
why the ZOOM didn't work.  Any suggestions?  Thanks, you might be saving my
sanity.

tif@doorstop.austin.ibm.com (Paul Chamberlain) (07/17/90)

In article <23885@adm.BRL.MIL> TSARS@uga.cc.uga.edu ( mark porporino) writes:
>I see the message "Serial: ERROR: Garbage or loose cable on
>/dev/tty1A, port shut down" on my console when a call comes in to my external
>2400bps ZOOM modem.

I seem to recall something like this:

The driver received an interrupt but there was no character received.  I
believe that the reason for this is that some UARTS can/will generate an
interrupt on RI (Ring Indicator).  SCO considers this a no-no.  I'm not
real sure but it seems like one solution was to disconnect RI from the UART.

Paul Chamberlain | I do NOT represent IBM         tif@doorstop, sc30661@ausvm6
512/838-7008     | ...!cs.utexas.edu!ibmaus!auschs!doorstop.austin.ibm.com!tif

jra@techdata.UUCP (Jay R. Ashworth) (07/23/90)

The Garbage or loose cable message means that the driver got more interrupts
than it thinks sane in a short period.  Sounds like a firmware problem to me.

Course, maybe you've just got a loose cable... :-)
-- jra

bob@rscsys.UUCP (Bob Celmer) (07/23/90)

In article <2775@awdprime.UUCP> tif@doorstop.austin.ibm.com (Paul Chamberlain) writes:
>In article <23885@adm.BRL.MIL> TSARS@uga.cc.uga.edu ( mark porporino) writes:
>>I see the message "Serial: ERROR: Garbage or loose cable on
>>/dev/tty1A, port shut down" on my console when a call comes in to my external
>>2400bps ZOOM modem.



First make sure that your modem is properly set.  Your modem initialization
string should include the the commands "Q1" and "E0".  The Q1 command will
prevent the modem from sending the system a "RING" string when a call comes
in.  This is very likely the problem.



-- 
Bob Celmer
UUCP: {fedeva,chromc}!dynasys!rscsys!bob