From: matt@centerline.com (Matt Landau)
Newsgroups: comp.sys.sun.admin
Subject: Zoom modem revisited [aka, IPC serial ports at >9600 baud?]
Date: 24 Nov 1992 01:04:40 GMT
Organization: CenterLine Software, Inc.
NNTP-Posting-Host: 140.239.1.32

A while back I posted a query asking for help getting an NCD to talk 
XRemote to my IPC running SunOS 4.1.1 over voice grade phone lines, 
using a pair of Zoom V42.bis modems on each end of the connection to
attain reasonable speeds and reasonable performance.

Although I received many helpful replies at the time, I haven't posted 
the promised summary because things still aren't *quite* working.  To
be a bit more specific, I have the NCD talking to its modem at 38.4K
quite nicely, and I have the two modems talking to each other at 14.4K
also quite nicely.  

(They don't talk faster because I've disabled all data compression and 
error checking, as per NCD's recommendation when running XRemote.  But
I have to wonder if XRemote *really* does better on its own that you 
could do with 56KB data rates using serious data compression...)

However, I cannot for the life of me get the IPC to talk to its modem
at speeds greater than 9600 baud.  Running at 9600 baud, things are 
just peachy -- I can dial up from the NCD, get a connection, run the
XRemote stuff, whatever.  But there's not much point in having a 14.4K 
connection between the modems if the Sun will only pump bits out at 9600 
baud.  However, trying to push the Sun into doing 14.4 or 19.2 results 
in complete failure.  The connection is made between the modems alright, 
but getty never recognizes it and never spwans a login.  

At best (with a minimal gettytab entry for "std.19200") I get the usual 
"wrong baudrate" behavior where typing at the NCD emits several garbage
characters per keystroke.  At worst (ie, if I try to enable autobauding
in getty), I get a couple of screens full of garbage spit at the NCD by
the IPC, followed by one side of the other dropping carrier.

This sounds a lot like a baudrate problem in gettytab or something, but 
damned if I can figure out what.  So what's the trick to getting an IPC 
running SunOS 4.1.1 to drive its serial ports at 14.4 or 19.2?  

For the sake of completeness, here's all of the information I can imaging
might be relevant.  

For what it's worth, trying to run "ttysoftcar -a" by hand after boot 
time just seems to hang.  I have no idea what this means, though.


[1] Relevant /etc/gettytab entries:

	default:\
        	:ap:lm=\r\n%h login\72 :sp#9600:
	2|std.9600|9600-baud:\
        	:sp#9600:ht:
	i|std.14400|14400-baud:\
        	:sp#14400:ht:
	g|std.19200|19200-baud:\
        	:sp#19200:ht:
	h|std.38400|38400-baud:\
        	:sp#38400:ht:


[2] Relevant /etc/ttytab entries:

	# Note: /dev/ttya and /dev/ttyb are commented out intentionally.

	console "/usr/etc/getty std.9600"       sun             on local secure
	ttyd0   "/usr/etc/getty std.19200"      dialup          on remote 
	cua0    "/usr/etc/getty std.9600"       unknown         off 
	#ttya   "/usr/etc/getty std.9600"       unknown         off
	#ttyb   "/usr/etc/getty std.9600"       unknown         off


[3] Relevant device entries in /dev

	% ls -li /dev/ttya /dev/ttyb /dev/ttyd0 /dev/cua0
	/dev/ttya not found
	/dev/ttyb not found
 	10790 crw-rw-rw-  1 uucp      12, 128 Nov 23 19:40 /dev/cua0
 	10772 crw--w--w-  1 root      12,   0 Nov 23 19:46 /dev/ttyd0

[4] Relevant values from "eeprom"

	ttyb-mode=9600,8,n,1,-
	ttya-mode=19200,8,n,1,-
	ttyb-rts-dtr-off=false
	ttyb-ignore-cd=false
	ttya-rts-dtr-off=false
	ttya-ignore-cd=false

[5] default modem configuration

	% tip cua0
	connected

ACTIVE PROFILE:
B1 E0 L0 M1 N1 P Q2 V1 W0 X4 Y0 &C1 &D0 &G0 &J0 &K5 &Q5 &R0 &S0 &T4 &X0 &Y0
S00:002 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:050 S08:002 S09:006
S10:014 S11:095 S12:050 S18:000 S25:005 S26:001 S36:007 S37:011 S38:020 S44:003
S46:136 S48:007 S49:008 S50:255 

So, does anyone have a clue here?  Why is serial configuration for Suns
such a black art in the first place?

Thanks for any and all suggestions...
--
 Matt Landau			Waiting for a flash of enlightenment
 matt@centerline.com			  in all this blood and thunder
Newsgroups: comp.sys.sun.admin