SUMMARY: SunOS 4.1.1 and telebit modem setup

From: Leon Howorth (
Date: Mon Jan 14 1991 - 17:17:54 CST

Thanks for the responses. Problem has been resolved. This was my
original posting:
I just upgraded a SUN 4/280 from OS 4.0.3 to OS 4.1.1. The machine
has a telebit trailblazer connected to serial port B.
I reinstalled the modem and it works alright for INCOMING calls
but I cannot seem to connect to it for outgoing calls. When I "tip"
to the modem I get an "all ports busy" message.

1. This is the appropriate line in config file from which the kernel
was made:
device zs0 at obio ? csr 0xf1000000 flags 1 priority 3

2. The device entries:
crw-rw-rw- 1 uucp staff 12, 129 Jan 11 11:14 cub
crw--w--w- 1 root wheel 12, 1 Jan 14 06:20 ttyd1

3. The entry in /etc/gettytab:

4. Entries in /etc/remote:

5. Appropriate lines in /etc/ttytab (ttyd1 replaces ttyb):
# name getty type status comments
console "/usr/etc/getty std.9600" vt100 on local secure
ttya "/usr/etc/getty std.9600" unknown off local secure
ttyd1 "/usr/etc/getty std.19200" dialup on local unsecure

The problem was twofold: I was not aware of the new
/usr/etc/ttysoftcar command, which is placed in /etc/rc in
OS 4.1.1, and I needed to change one of the telebit trailblazer

1. From the man page for ttysoftcar:

"For each tty specified ttysoftcar changes the carrier detect
flag using the TIOCSSOFTCAR ioctl() request (see tty(4)).
If the -a option is specified, ttysoftcar sets all tty's in
the /etc/ttytab file to the carrier detection mode specified
by their status field. If this field is set to local,
software carrier detection is turned on. If this field is
set to anything other than local, as is usually the case for
modems, software carrier detection is turned off."

Therefore I changed my /etc/ttytab line from:
ttyd1 "/usr/etc/getty std.19200" dialup on local unsecure

ttyd1 "/usr/etc/getty std.19200" dialup on remote unsecure

and rebooted the machine.

(Note: Some also pointed out the importance of checking for any lock
files in /var/spool/locks when the message "all ports busy" is
received. This was not the problem in this case, but is a good idea).

2. I needed to change the S53 register on my telebit trailblazer (prom
version 4.00) from S53=3 to S53=1. This is defined as: "DSR is ON when the
modem is ready to accept commands or data. DCD is ON when the carrier is

The modem is now set up to answer calls with auto speed determination
and I can "tip cub" to use it for outgoing calls. The register settings
are as follows:

E1 F1 M1 Q6 T V1 X1 Version BA4.00
S00=001 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=040 S08=002 S09=006
S10=007 S11=070 S12=050
S45=255 S47=004 S48=000 S49=000
S50=000 S51=005 S52=001 S53=001 S54=003 S55=000 S56=017 S57=019 S58=003 S59=000
S60=000 S61=045 S62=003 S63=001 S64=000 S65=000 S66=001 S67=000 S68=255
S90=000 S91=000 S92=000 S95=000
S100=000 S101=000 S102=000 S104=000
S110=001 S111=010 S112=001

Leon A. Howorth | UUCP: ....princeton!hhb!leonh
Systems and Network Manager | ARPA:
Racal-Redac | VOICE: 201-848-8000 ext. 243
Mahwah, New Jersey 07430 | FAX: 201-848-8189

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