SUMMARY: Sparc won't boot with modems attached

[David Mostardi]

I recently noticed that my SparcStation 1 (running 4.1) wouldn't boot if
my modems were attached to ttya or ttyb (a cold boot wouldn't even get as
far as "Testing").  As soon as I unplugged them, the boot sequence
continued.  The problem remains unresolved to this day.  I talked to a Sun
tech, who said that she remembered a problem like this.

I then asked the Sun group this question:

>Is it *really* true that a Sparcstation 1 won't boot if there are any
>devices (say, modems) attached to the serial ports?  The techie at Sun
>believes this is true.  Is there any way around this incredible problem?

I received many replies: some said "nonsense", others "you bet".  Enough
people agreed with me that I'm assuming there is some sort of
hardware-level problem here.  The tech at Sun has not been returning my
calls or messages.  Here is a summary of the responses:

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From: dgh at Eng.Sun.COM (David Hough)

I have a 4/60 at home with a  modem and laserwriter on the serial ports.
Boots fine.

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From: rhoward at msd.gatech.edu

I can't believe that this is true!  You mean to say we have to disconnect
everything whenever we need to do a reboot?  I'd love to hear the outcome
of this.

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From: eggert at twinsun.com (Paul Eggert)

Not true; we do it all the time.  However, you're out of luck if the
device is sending characters to the Sun at the time.  The SS1 may think
that the device is the console and can be halted by BREAKs, for example.
Sun knows about this problem but I'm not holding my breath waiting for
them to fix it.

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From: jem at matt.ksu.ksu.edu (James Morrill)

We have a Sun 4/60, running 4.0.3 OS and we've seen this problem.  We have
a modem, a terminal, and a printer off this SPARC and we can't reboot if
the terminal is turned OFF.  It reboots fine as long as everything is ON,
although I've never tried rebooting with the modem or printer turned off,
as they just stay on all the time.  If the machine reboots and the
terminal is off, I just unplug the serial line from that terminal, and
then the SPARC reboots fine.

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From: mmikulska at UCSD.EDU (Margaret Mikulska)

Among the systems I manage, we have at least three SS-1s with printers on
their serial ports. There are absolutely no problems with booting them.
(I can't tell about modems, though.)

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From: mike at nmr-z.MGH.Harvard.Edu (Mike Vevea)

No, it doesn't seem to be true.  I've got a modem on my Sparcstation I
(NOT a 1+), and it boots fine.

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From: hanson at fnal.gov (Steve Hanson)

Well, by golly, this is news to me.  I've had one with a modem and one
with a printer, and I think I would have noticed if they didn't boot.
Like, I'd be having a hard time sending you this note if this machine
hadn't booted.

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From: tessi!joey at nosun.West.Sun.COM (Joe Pruett)

We have a ss1+ with a modem and printer attached and have no problem with
booting.

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From: ang at theory.lcs.mit.edu (William S. Ang)

Yes, it is true IF your device is connected to ttya.  I have all my
printers, modems, terminals, etc., on ttyb serial ports and they all
rebooted fine.

The problem with ttya is that it is the alternate console port. The
machine thinks that you have a terminal attached to it and start talking
to the ttya port when booting.

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From: tcurrey at x102a.ess.harris.com (currey tom 76327)

The problem is in the ROM chips.  To bypass this problem well to get
around it. Just make sure the device connected is powered on.  Also, you
might use port B. I don't remeber if there was a bug in that port also.

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From: ekrell at ulysses.att.com

Nonsense. I have a printer attached to a serial port and I can boot it
just fine. I can't believe someone from Sun told you that ...

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From: Greg Onufer <greg at cheers.Bungi.COM>

Yes, I think I have heard of this problem.  Mail a note to keyman at Sun.COM
and ask him about it.  He may be able to help you (I think he may have
told me about it). 

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From: Dave Morton <dave at ecrc.de>

Yes it's true I'm afraid. There are patches to the stock 4.0.3c OS that
get it to work. Sun should be able to give you the patches.

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From: ajudge%maths.tcd.ie at pucc.PRINCETON.EDU

No. We have one Sparcstation 1 with a printer attached to ttya and one
with a terminal on ttya. Both boot fine. There may, however, be problems
with modems due to hardware flow control and DTR/DSR/CD.

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From: gwcook at Sun.COM (Gary Cook - CS Mgr - Latin America)

If my memory is correct, this can be fixed by replacing the boot prom with
the latest revision.  Let me know what version it is and I will tell you
if that is your problem.

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From: mis at seiden.com (Mark Seiden)

yeah, there's a serial and alm patch tape which i heard fixes the problem.
i think it gets confused if there's something that could look like a
console on serial a...

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From: peter at klatu.key.com (Peter Sivo)

Yep....  We have a few 3/80 machines that won't boot because a digitizer
Autocad device is plugged into /dev/ttya.

Everytime we reboot, we have to unplug it, wait until the banner comes up,
and then plug it back in.

According to SUN, there is a certain REV. level of CPU boards that have
this problem, but supposedly it has been fixed in the new machines.

I must admit, out of the 15 3/80's we have, ONLY 3 have this problem....