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* Re: [9fans] serial reboot boxes
@ 2006-01-09  8:26 Fco. J. Ballesteros
  2006-01-09  8:46 ` Steve Simon
  2006-01-09  9:28 ` Skip Tavakkolian
  0 siblings, 2 replies; 25+ messages in thread
From: Fco. J. Ballesteros @ 2006-01-09  8:26 UTC (permalink / raw)
  To: 9fans

:  
:  I know Dan Ridge uses X10 stuff for lots of remote lighting
:  and appliance control applications via a little web interface...

X10 is not reliable. But if you go for it, x10/fs in the planb distrib
works also for Plan 9.



^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  8:26 [9fans] serial reboot boxes Fco. J. Ballesteros
@ 2006-01-09  8:46 ` Steve Simon
  2006-01-09 11:09   ` Skip Tavakkolian
  2006-01-09 15:27   ` Ronald G Minnich
  2006-01-09  9:28 ` Skip Tavakkolian
  1 sibling, 2 replies; 25+ messages in thread
From: Steve Simon @ 2006-01-09  8:46 UTC (permalink / raw)
  To: 9fans

Maybe I'am alone in this, but I would like to find a tiny, single board
computer that would run plan9. It would need to have ethernet, one or two
serial ports, and some general perpose I/Os. I would chose an PPC or ARM cpu
and a price-point of around $50.

If I had such an SBC I would write an app to set the GPIOs and which
could control mains relays or reset pins on CPU servers:

	cpu -h sysctl -c gpio -waggle pin2

One of these would also become my auth server.

-Steve


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  8:26 [9fans] serial reboot boxes Fco. J. Ballesteros
  2006-01-09  8:46 ` Steve Simon
@ 2006-01-09  9:28 ` Skip Tavakkolian
  1 sibling, 0 replies; 25+ messages in thread
From: Skip Tavakkolian @ 2006-01-09  9:28 UTC (permalink / raw)
  To: 9fans


how about a parallel reboot kit?
www.alltronics.com is selling them for < $50

http://www.kitsrus.com/pdf/k74v2.pdf



^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09 11:09   ` Skip Tavakkolian
@ 2006-01-09 10:12     ` Charles Forsyth
  0 siblings, 0 replies; 25+ messages in thread
From: Charles Forsyth @ 2006-01-09 10:12 UTC (permalink / raw)
  To: 9fans

> but then, with all those 486 and pentium pc's being discarded, why not
> get that kit#74 from kitsrus.com and hook it up to an old pc running
> plan9, and a little elbow grease and call it done?

in my case, space and power consumption



^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  8:46 ` Steve Simon
@ 2006-01-09 11:09   ` Skip Tavakkolian
  2006-01-09 10:12     ` Charles Forsyth
  2006-01-09 15:27   ` Ronald G Minnich
  1 sibling, 1 reply; 25+ messages in thread
From: Skip Tavakkolian @ 2006-01-09 11:09 UTC (permalink / raw)
  To: 9fans

> Maybe I'am alone in this, but I would like to find a tiny, single board
> computer that would run plan9. It would need to have ethernet, one or two
> serial ports, and some general perpose I/Os. I would chose an PPC or ARM cpu
> and a price-point of around $50.

would you need all that?  following the Styx-on-a-Brick example (Lego
Mindstorms), all you need is something with enough cpu to talk 9p to
export a name space from the gizmo.

but then, with all those 486 and pentium pc's being discarded, why not
get that kit#74 from kitsrus.com and hook it up to an old pc running
plan9, and a little elbow grease and call it done?



^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  8:46 ` Steve Simon
  2006-01-09 11:09   ` Skip Tavakkolian
@ 2006-01-09 15:27   ` Ronald G Minnich
  2006-01-09 15:32     ` William Josephson
  1 sibling, 1 reply; 25+ messages in thread
From: Ronald G Minnich @ 2006-01-09 15:27 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

Steve Simon wrote:
> Maybe I'am alone in this, but I would like to find a tiny, single board
> computer that would run plan9. It would need to have ethernet, one or two
> serial ports, and some general perpose I/Os. I would chose an PPC or ARM cpu
> and a price-point of around $50.

how about $134? the ts/7200 is pretty good.

ron


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09 15:27   ` Ronald G Minnich
@ 2006-01-09 15:32     ` William Josephson
  2006-01-09 15:36       ` Ronald G Minnich
  0 siblings, 1 reply; 25+ messages in thread
From: William Josephson @ 2006-01-09 15:32 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

On Mon, Jan 09, 2006 at 08:27:24AM -0700, Ronald G Minnich wrote:
> Steve Simon wrote:
>>Maybe I'am alone in this, but I would like to find a tiny, single board
>>computer that would run plan9. It would need to have ethernet, one or two
>>serial ports, and some general perpose I/Os. I would chose an PPC or ARM 
>>cpu and a price-point of around $50.
> 
>how about $134? the ts/7200 is pretty good.

Have one with a second or third ethernet port?
I wish the PowerPC-based firewall bricks from 1127
were available in some form.


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09 15:32     ` William Josephson
@ 2006-01-09 15:36       ` Ronald G Minnich
  0 siblings, 0 replies; 25+ messages in thread
From: Ronald G Minnich @ 2006-01-09 15:36 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

William Josephson wrote:
> On Mon, Jan 09, 2006 at 08:27:24AM -0700, Ronald G Minnich wrote:
> 
>>Steve Simon wrote:
>>
>>>Maybe I'am alone in this, but I would like to find a tiny, single board
>>>computer that would run plan9. It would need to have ethernet, one or two
>>>serial ports, and some general perpose I/Os. I would chose an PPC or ARM 
>>>cpu and a price-point of around $50.
>>
>>how about $134? the ts/7200 is pretty good.
> 
> 
> Have one with a second or third ethernet port?
> I wish the PowerPC-based firewall bricks from 1127
> were available in some form.

hmm, how about cheap epia boards with two enets?

ron


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
                   ` (6 preceding siblings ...)
  2006-01-09 12:38 ` Derek Fawcus
@ 2006-01-09 15:47 ` Martin Harriss
  7 siblings, 0 replies; 25+ messages in thread
From: Martin Harriss @ 2006-01-09 15:47 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

Russ,

Quality solid state AC relays may be obtained at reasonable prices from:

Digikey (www.digikey.com)
Mouser (www.mouser.com)

Be careful though - some of them may be thyristor (half wave) output 
rather than Triac (full wave) output.

I'd be happy to assist in selecting a suitable component if it would help.

Martin
(for whom building hardware is yet another activity to occupy his 
Copious Free Time.)


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09 12:38 ` Derek Fawcus
@ 2006-01-09 12:44   ` Derek Fawcus
  0 siblings, 0 replies; 25+ messages in thread
From: Derek Fawcus @ 2006-01-09 12:44 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

On Mon, Jan 09, 2006 at 12:38:59PM +0000, Derek Fawcus wrote:
> 
> I'll have a look tomorrow to see if I can dig out the details.

... and I just noticed a reference to the boxes...

Network Power Switches
Models NPS-115 & NPS-230

http://www.wti.com/

DF


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
                   ` (5 preceding siblings ...)
  2006-01-09  3:20 ` jmk
@ 2006-01-09 12:38 ` Derek Fawcus
  2006-01-09 12:44   ` Derek Fawcus
  2006-01-09 15:47 ` Martin Harriss
  7 siblings, 1 reply; 25+ messages in thread
From: Derek Fawcus @ 2006-01-09 12:38 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

On Sun, Jan 08, 2006 at 01:34:41PM -0500, Russ Cox wrote:
> (This is slightly off-topic, but since Plan 9 users seem to be the
> only ones using serial consoles anymore...)

> Does anyone know where to buy the simple version for cheap?

We use this sort of thing in our racks for rebooting crashed
routers (i.e. when the development images hangs).

They are a normal rack mounted piece of kit.  Having a serial
port and (I think) an ethernet port,  but we only connect via
the serial port.

I'll have a look tomorrow to see if I can dig out the details.

DF


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  3:20 ` jmk
  2006-01-09  5:01   ` Ronald G Minnich
  2006-01-09  5:51   ` Skip Tavakkolian
@ 2006-01-09  6:08   ` Martin C. Atkins
  2 siblings, 0 replies; 25+ messages in thread
From: Martin C. Atkins @ 2006-01-09  6:08 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

On Sun, 8 Jan 2006 22:20:03 -0500 jmk@plan9.bell-labs.com wrote:
>..
> a lot less strain on the system than a remote power switch (we
> have an APC one and it requires wading through menus in both serial
> and web access modes).

If you've got the one I've seen, I thought it could also be commanded
by SNMP - not the most elegant protocol, but it should avoid the menus!
Is there a gotcha I didn't notice?

Martin

> 
> --jim


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  3:20 ` jmk
  2006-01-09  5:01   ` Ronald G Minnich
@ 2006-01-09  5:51   ` Skip Tavakkolian
  2006-01-09  6:08   ` Martin C. Atkins
  2 siblings, 0 replies; 25+ messages in thread
From: Skip Tavakkolian @ 2006-01-09  5:51 UTC (permalink / raw)
  To: 9fans

> I'm sure there's someone out there with enough hardware smarts to
> produce a replacement, it really is a great thing to have and it's
> a lot less strain on the system than a remote power switch (we
> have an APC one and it requires wading through menus in both serial
> and web access modes).

for me it doesn't happen often enough to worry about, but maybe
i should.

i have a couple of suggestions for the relays.  CircuitCellar probably
has done a project like this. It might be worth a look.  Another cheaper
remote relay control i found is "webrelay" at www.controlbyweb.com.
its $99. still seems like a lot.



^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  5:16     ` Devon H. O'Dell
@ 2006-01-09  5:27       ` jmk
  0 siblings, 0 replies; 25+ messages in thread
From: jmk @ 2006-01-09  5:27 UTC (permalink / raw)
  To: 9fans

On Mon Jan  9 00:20:50 EST 2006, devon.odell@gmail.com wrote:
> ...
> You could use a parallel port to control more than 1 device. With
> output and ground, you could use a microcontroller (or probably some
> gates, but my EE skills suck) to determine which pins are set and have
> an 8 bit mask to control up to 255 devices, I think.
> ...
> --Devon

i think we decided on using 5 bits to select the device and
one bit as an enable. i don't remember if the other two bits
were used but 32 was more than enough for our little setup.

--jim


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  5:01   ` Ronald G Minnich
@ 2006-01-09  5:16     ` Devon H. O'Dell
  2006-01-09  5:27       ` jmk
  0 siblings, 1 reply; 25+ messages in thread
From: Devon H. O'Dell @ 2006-01-09  5:16 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

2006/1/8, Ronald G Minnich <rminnich@lanl.gov>:
> But: you can get reed relays from radio shack. Wire the contacts of the
> reed relay across RST. Drive the relay coil from one of 8 parallel ports
> of a PC. Voila, 8 remote resets. I did use these relays once for a
> remote doorbell, and I can tell you that you could even use the remote
> doorbell + reed relay combo for reset ... that would be amusing. Ring
> the doorbell, reset the rack of machines. The doorbells have multiple
> selectable channels. Fun.

You could use a parallel port to control more than 1 device. With
output and ground, you could use a microcontroller (or probably some
gates, but my EE skills suck) to determine which pins are set and have
an 8 bit mask to control up to 255 devices, I think.

--Devon

> If you have more time than money, this will work. We have more money
> than time, so we use ICE and similar stuff.
>
> ron

Ha. I'd go for a balance between the two :S

--Devon


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-09  3:20 ` jmk
@ 2006-01-09  5:01   ` Ronald G Minnich
  2006-01-09  5:16     ` Devon H. O'Dell
  2006-01-09  5:51   ` Skip Tavakkolian
  2006-01-09  6:08   ` Martin C. Atkins
  2 siblings, 1 reply; 25+ messages in thread
From: Ronald G Minnich @ 2006-01-09  5:01 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

oh dear, we're going to go into memory lane.

In the 70s, for our 8-bit 6800 systems, we set up so that BRK would 
produce a reset. This was good, since the ASR-33 had a BRK key. Since 
BRK would work fine from ASR-33 -> modem -> modem -> 6800, we had remote 
reset. I will say no more.

On a coupla thousand nodes here, we have these ICE boxes from Linux 
NetworX that are interesting. You telnet in, and they talk to a little 
module in the box over I2C. Said module can assert reset. You tell said 
module to do it, voila, done. It can also assert soft power cycle. And, 
finally, the ICE box can cycle the AC power. Very, very flexible, and 
very, very useful.

Sometimes, you really want to cycle the AC, sometimes the soft power 
supply, sometimes the reset. For doing reset, well, hmm, the ICE box is 
pricey.

But: you can get reed relays from radio shack. Wire the contacts of the 
reed relay across RST. Drive the relay coil from one of 8 parallel ports 
of a PC. Voila, 8 remote resets. I did use these relays once for a 
remote doorbell, and I can tell you that you could even use the remote 
doorbell + reed relay combo for reset ... that would be amusing. Ring 
the doorbell, reset the rack of machines. The doorbells have multiple 
selectable channels. Fun.

If you have more time than money, this will work. We have more money 
than time, so we use ICE and similar stuff.

ron


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
                   ` (4 preceding siblings ...)
  2006-01-09  0:08 ` David Leimbach
@ 2006-01-09  3:20 ` jmk
  2006-01-09  5:01   ` Ronald G Minnich
                     ` (2 more replies)
  2006-01-09 12:38 ` Derek Fawcus
  2006-01-09 15:47 ` Martin Harriss
  7 siblings, 3 replies; 25+ messages in thread
From: jmk @ 2006-01-09  3:20 UTC (permalink / raw)
  To: 9fans

When I first worked in the US I worked with Brian Redman who
held a patent on the box used widely within Bell Labs which allowed
simultaneous access to a computer's serial console from both the
physical console and another serial line, usually connected to
either a modem or a Datakit node (Redman et al, 4479122, Remote
controlled switched access to the console port of an electronic
computer). We still have many of these boxes. However, there was
a variant box which had another serial input port which activated
a relay between two extra output lines when CTS (?) was asserted.
These lines could be attached to the reset pins on a conmputer
to cause it to to the right thing. At some point in the 90s most
of these were thrown out when I wasn't looking. I have one left
and it lets me reboot my test system remotely by simply
	C office2</dev/null
where office2 is a serial port on a console server to which the
reboot box is attached.

Three or four years ago I started work on a replacement with a
hardware guy here, it was going to use the parallel port and a
CAT5 patch panel to access to a bunch of computers. Unfortunately
my colleague took the eary retirement package before we got it
past the planning stages.

I'm sure there's someone out there with enough hardware smarts to
produce a replacement, it really is a great thing to have and it's
a lot less strain on the system than a remote power switch (we
have an APC one and it requires wading through menus in both serial
and web access modes).

--jim


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
                   ` (3 preceding siblings ...)
  2006-01-08 22:23 ` William Josephson
@ 2006-01-09  0:08 ` David Leimbach
  2006-01-09  3:20 ` jmk
                   ` (2 subsequent siblings)
  7 siblings, 0 replies; 25+ messages in thread
From: David Leimbach @ 2006-01-09  0:08 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

[-- Attachment #1: Type: text/plain, Size: 2144 bytes --]

On 1/8/06, Russ Cox <rsc@swtch.com> wrote:
>
> (This is slightly off-topic, but since Plan 9 users seem to be the
> only ones using serial consoles anymore...)


That's a bad assumption.  People use serial consles A LOT.

In fact there are things like  serial port concentrators that allow people
to remotely manage boxes out of band and to do extra debugging on systems
that may or may not have any network connectivity whatsoever.  Companies pay
really big money for these devices too.

Serial console may die someday but it's going to take a lot more than some
of the KVM technology I've seen to do it.  [and I've seen a lot, it's too
complicated still.]


At Bell Labs we have a handful of custom-built boxes
> that help reboot machines.  I never knew how they worked
> inside or even what the inputs and outputs were, but
> if you asserted CTS on a serial line connected to one,
> they'd make the attached computer reboot.  I think they
> were doing AC power cycling.
>
> I built a box of similar functionality myself ten years ago.
> I went through a few designs but eventually ended up with
> a solid-state AC relay being driven by a serial line.  I saved
> a sketch of the circuit but have since misplaced it.
> I don't know where the box ended up either.
> I don't remember it costing very much money (certainly
> no more than $20) to buy the parts from Radio Shack.
>
> I would like a few more of these.  Rather than build them,
> I went online looking for such.  I can't find any.  I found ones
> with ethernet controllers and web servers, but those are
> $300 apiece (usually for a handful of outlets), and all I
> really want is just one outlet and one serial port.



Sounds like an iBoot.  It's a web interfaced chunk o' hardware that can
remotely powercycle a box.  The ones I've tried didn't work very well and
themselves would hang.


Does anyone know where to buy the simple version for cheap?
>
> Failing that, does anyone know where to buy cheap solid-state
> AC relays?  The ones I've found have all been $100+, which
> doesn't seem right to me.
>
> Thanks.
> Russ
>

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^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:53 ` erik quanstrom
@ 2006-01-08 22:37   ` Skip Tavakkolian
  2006-01-08 21:48     ` erik quanstrom
  0 siblings, 1 reply; 25+ messages in thread
From: Skip Tavakkolian @ 2006-01-08 22:37 UTC (permalink / raw)
  To: 9fans

> i believe that apc power supplies have a serial connection and
> should be able to cycle the power. it's been a while on those.

I was going to suggest a similar approach.  I use a couple of
Tripp-Lite UPS's that have a USB interface (6 outlets, i think ~70$).
I started to look into this but never finished.  I downloaded their
GNU licensed server and client for Linux.  Besides sending alerts, the
UPS apparently can accept commands for shutting it off, rebooting it,
and shutting receptacles on/off.



^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
                   ` (2 preceding siblings ...)
  2006-01-08 22:12 ` Steve Simon
@ 2006-01-08 22:23 ` William Josephson
  2006-01-09  0:08 ` David Leimbach
                   ` (3 subsequent siblings)
  7 siblings, 0 replies; 25+ messages in thread
From: William Josephson @ 2006-01-08 22:23 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

On Sun, Jan 08, 2006 at 01:34:41PM -0500, Russ Cox wrote:
> Failing that, does anyone know where to buy cheap solid-state
> AC relays?  The ones I've found have all been $100+, which
> doesn't seem right to me.

I know Dan Ridge uses X10 stuff for lots of remote lighting
and appliance control applications via a little web interface...


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
  2006-01-08 18:53 ` erik quanstrom
  2006-01-08 21:13 ` Ronald G Minnich
@ 2006-01-08 22:12 ` Steve Simon
  2006-01-08 22:23 ` William Josephson
                   ` (4 subsequent siblings)
  7 siblings, 0 replies; 25+ messages in thread
From: Steve Simon @ 2006-01-08 22:12 UTC (permalink / raw)
  To: 9fans

Re: solid state relays.

If you really want to switch mains RS or Farnell are the traditional
suppliers for such things in the UK - both of wholm have offices
worldwide these days.

I would suggest a little 8 bin DIL device attached to the reset lines
for the offending machine. There is (usually) no need to cycle power
and the stress on its PSU and disks this implies.

http://www.farnell.com
http://www.rs-components.com

-Steve


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 22:37   ` Skip Tavakkolian
@ 2006-01-08 21:48     ` erik quanstrom
  0 siblings, 0 replies; 25+ messages in thread
From: erik quanstrom @ 2006-01-08 21:48 UTC (permalink / raw)
  To: 9fans, Skip Tavakkolian

that shows you how long ago i looked at this.
i had a upas with a db-9 serial connector.

- erik

Skip Tavakkolian <9nut@9netics.com> writes

| 
| > i believe that apc power supplies have a serial connection and
| > should be able to cycle the power. it's been a while on those.
| 
| I was going to suggest a similar approach.  I use a couple of
| Tripp-Lite UPS's that have a USB interface (6 outlets, i think ~70$).
| I started to look into this but never finished.  I downloaded their
| GNU licensed server and client for Linux.  Besides sending alerts, the
| UPS apparently can accept commands for shutting it off, rebooting it,
| and shutting receptacles on/off.


^ permalink raw reply	[flat|nested] 25+ messages in thread

* Re: [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
  2006-01-08 18:53 ` erik quanstrom
@ 2006-01-08 21:13 ` Ronald G Minnich
  2006-01-08 22:12 ` Steve Simon
                   ` (5 subsequent siblings)
  7 siblings, 0 replies; 25+ messages in thread
From: Ronald G Minnich @ 2006-01-08 21:13 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

have you looked at the x10 stuff? Long ago I used the X-10 stuff (just 
bought it from radio shack) to control a monitor wall. Worked really 
well. I think there are X-10 serial interface controllers out there.

ron


^ permalink raw reply	[flat|nested] 25+ messages in thread

* [9fans] serial reboot boxes
  2006-01-08 18:34 Russ Cox
@ 2006-01-08 18:53 ` erik quanstrom
  2006-01-08 22:37   ` Skip Tavakkolian
  2006-01-08 21:13 ` Ronald G Minnich
                   ` (6 subsequent siblings)
  7 siblings, 1 reply; 25+ messages in thread
From: erik quanstrom @ 2006-01-08 18:53 UTC (permalink / raw)
  To: 9fans, Russ Cox

i believe that apc power supplies have a serial connection and
should be able to cycle the power. it's been a while on those.

when i worked at ibm we had a watchdog program monitored
the serial line and rebooted the computer if CTS was high.
this might work for you if the kernel is still living, but some
of the services are confused.

- erik

Russ Cox <rsc@swtch.com> writes

| 
| (This is slightly off-topic, but since Plan 9 users seem to be the
| only ones using serial consoles anymore...)
| 
| At Bell Labs we have a handful of custom-built boxes
| that help reboot machines.  I never knew how they worked
| inside or even what the inputs and outputs were, but
| if you asserted CTS on a serial line connected to one,
| they'd make the attached computer reboot.  I think they
| were doing AC power cycling.
| 
| I built a box of similar functionality myself ten years ago.
| I went through a few designs but eventually ended up with
| a solid-state AC relay being driven by a serial line.  I saved
| a sketch of the circuit but have since misplaced it.
| I don't know where the box ended up either.
| I don't remember it costing very much money (certainly
| no more than $20) to buy the parts from Radio Shack.
| 
| I would like a few more of these.  Rather than build them,
| I went online looking for such.  I can't find any.  I found ones
| with ethernet controllers and web servers, but those are
| $300 apiece (usually for a handful of outlets), and all I
| really want is just one outlet and one serial port.
| 
| Does anyone know where to buy the simple version for cheap?
| 
| Failing that, does anyone know where to buy cheap solid-state
| AC relays?  The ones I've found have all been $100+, which
| doesn't seem right to me.
| 
| Thanks.
| Russ


^ permalink raw reply	[flat|nested] 25+ messages in thread

* [9fans] serial reboot boxes
@ 2006-01-08 18:34 Russ Cox
  2006-01-08 18:53 ` erik quanstrom
                   ` (7 more replies)
  0 siblings, 8 replies; 25+ messages in thread
From: Russ Cox @ 2006-01-08 18:34 UTC (permalink / raw)
  To: 9fans

(This is slightly off-topic, but since Plan 9 users seem to be the
only ones using serial consoles anymore...)

At Bell Labs we have a handful of custom-built boxes
that help reboot machines.  I never knew how they worked
inside or even what the inputs and outputs were, but
if you asserted CTS on a serial line connected to one,
they'd make the attached computer reboot.  I think they
were doing AC power cycling.

I built a box of similar functionality myself ten years ago.
I went through a few designs but eventually ended up with
a solid-state AC relay being driven by a serial line.  I saved
a sketch of the circuit but have since misplaced it.
I don't know where the box ended up either.
I don't remember it costing very much money (certainly
no more than $20) to buy the parts from Radio Shack.

I would like a few more of these.  Rather than build them,
I went online looking for such.  I can't find any.  I found ones
with ethernet controllers and web servers, but those are
$300 apiece (usually for a handful of outlets), and all I
really want is just one outlet and one serial port.

Does anyone know where to buy the simple version for cheap?

Failing that, does anyone know where to buy cheap solid-state
AC relays?  The ones I've found have all been $100+, which
doesn't seem right to me.

Thanks.
Russ


^ permalink raw reply	[flat|nested] 25+ messages in thread

end of thread, other threads:[~2006-01-09 15:47 UTC | newest]

Thread overview: 25+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-01-09  8:26 [9fans] serial reboot boxes Fco. J. Ballesteros
2006-01-09  8:46 ` Steve Simon
2006-01-09 11:09   ` Skip Tavakkolian
2006-01-09 10:12     ` Charles Forsyth
2006-01-09 15:27   ` Ronald G Minnich
2006-01-09 15:32     ` William Josephson
2006-01-09 15:36       ` Ronald G Minnich
2006-01-09  9:28 ` Skip Tavakkolian
  -- strict thread matches above, loose matches on Subject: below --
2006-01-08 18:34 Russ Cox
2006-01-08 18:53 ` erik quanstrom
2006-01-08 22:37   ` Skip Tavakkolian
2006-01-08 21:48     ` erik quanstrom
2006-01-08 21:13 ` Ronald G Minnich
2006-01-08 22:12 ` Steve Simon
2006-01-08 22:23 ` William Josephson
2006-01-09  0:08 ` David Leimbach
2006-01-09  3:20 ` jmk
2006-01-09  5:01   ` Ronald G Minnich
2006-01-09  5:16     ` Devon H. O'Dell
2006-01-09  5:27       ` jmk
2006-01-09  5:51   ` Skip Tavakkolian
2006-01-09  6:08   ` Martin C. Atkins
2006-01-09 12:38 ` Derek Fawcus
2006-01-09 12:44   ` Derek Fawcus
2006-01-09 15:47 ` Martin Harriss

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