Network control of many Macs

On 1/31/2005 3:43 PM, "curtis corlew" wrote:
> I'm scheduled to make a presentation in a school computer lab that
> has 30 networked Macs ringing the edge of the room.
> It occurred to me it would be quite an event if i could use every Mac
> in the room.
>
> I'd like to be able to have a flash (or something like it) movie
> running on each computer, but be able to control it from one on
> computer. Perhaps sending messages to the flash movie (again, it
> doesn't HAVE to be Flash) about what frame to go to.

Apple Remote Desktop can do this: You can send your screen to all of the
other screens in the lab.

> I could have a ball, or a talking head, circle the room and appear
> jump from Mac to Mac.

This would be a different story ;-)

At 3:43 PM -0800 1/31/05, curtis corlew wrote:
>But, alas, I don't know of any product, or group of products that
>are aimed at doing this. Do they exist?
>And hints on even the possibility of pulling off something like
>this, or even directing me elsewhere, would be greatly appreciated.

Timbuktu can do one-to-many screen broadcasts. From your Mac, Invite
the others to Observe your screen.

Apple Remote Desktop can do it to, from the Remote Desktop management
console. Just highlight the machines in in the machine list and
choose "Share Screen" from the Interact menu. You can force them all
to display your screen.

Both are bandwidth limited, obviously.

I've seen solutions which use hardware video switching to route
signals to/from/between computers.

Macromedia has something that'll do this too, but the name escapes me.

--
Andrew Laurence
atlaurenuci.edu

Curtis,
My initial reaction is a hardware solution. I know when I was at the
University of Michigan they had a hardware system which switched all
the screens in the lab to (1) the computer the monitor was connected
to (2) blank/no signal (3) a master feed of the instructor's screen.
This would end up being capital intensive and probably isn't what you
are looking for.

Another option though would be to come up with some web
server/browser based solution. You could start all the computers up
before the class starts then load a specific page that reloads itself
every 10s-1m or so (whatever best fits your presentation) When the
time comes to introduce your slide or Flash, etc.. you could have a
setup to change the file on the webserver (which could be presetup
via shell scripts etc..) So all the computers would reload the page
and get the next set. There might be other options you could work
out with flash directly via polling. (admittedly this isn't too
great for the webserver, but any descent machine should be able to
handle 30 hits at once.)

Nick

At 3:43 PM -0800 1/31/05, curtis corlew wrote:
>I'm scheduled to make a presentation in a school computer lab that
>has 30 networked Macs ringing the edge of the room.
>It occurred to me it would be quite an event if i could use every Mac
>in the room.
>
>I'd like to be able to have a flash (or something like it) movie
>running on each computer, but be able to control it from one on
>computer. Perhaps sending messages to the flash movie (again, it
>doesn't HAVE to be Flash) about what frame to go to.
>
>I could have a ball, or a talking head, circle the room and appear
>jump from Mac to Mac.
>
>But, alas, I don't know of any product, or group of products that are
>aimed at doing this. Do they exist?
>And hints on even the possibility of pulling off something like this,
>or even directing me elsewhere, would be greatly appreciated.
>--
>Curtis Corlew
>Los Medanos College, Pittsburg CA
>Personal page http://curtis.corlew.com

> I could have a ball, or a talking head, circle the room and appear
> jump from Mac to Mac.
>

Remote Apple Events and AppleScript will give you this flexibility. Of
course with great flexibility comes great learning curve ;-)

Or you could look at VersionTracker or Google some example programs
that use Remote Apple Events that may be equally impressive.

On first glance (ie, Google), Remote Remote is an app that controls
iTunes on a computer remotely -- and keeps a list of the computers...
so you could do something with iTunes and short sound files, causing
them to blip beep and cause a general ruckus throughout your
presentation... or perhaps something less annoying ;-)

mc

At 3:43 PM -0800 2005/01/31, curtis corlew wrote:
>I'm scheduled to make a presentation in a school computer lab that
>has 30 networked Macs ringing the edge of the room.
>It occurred to me it would be quite an event if i could use every Mac
>in the room.
>
>I'd like to be able to have a flash (or something like it) movie
>running on each computer, but be able to control it from one on
>computer. Perhaps sending messages to the flash movie (again, it
>doesn't HAVE to be Flash) about what frame to go to.
>
>I could have a ball, or a talking head, circle the room and appear
>jump from Mac to Mac.

        You can also play tricks with the open command via ssh.
Assuming you have an account on every machine, something like "dsh -N
class open http://teacher/slide1.html" or "dsh -N class open
/System/Library/CoreServices/Finder.app/" could be quite effective.

        To make this work, you need files, folders, or URLs (possibly
on the teacher's workstation) you can open for each "event". To make
it workable, I suggest Gentoo keychain (to avoid typing the
passphrase for every ssh invocation) and dsh (to execute one command
line across multiple machines).

http://www.gentoo.org/proj/en/keychain/
http://www.ccr.buffalo.edu/rappleye/dsh.html

        Then populate /util/beowulf/node_groups/class with the names
or IPs of all 30 machines, so "dsh -N class" works.

ssh-keygen -t dsa # make a public key

        Either (without dsh):
for h in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
24 25 26 27 28 29 30
do ssh host$d mkdir -p .ssh # create .ssh directory on each host, if necessary
done

        Or (with dsh):
dsh -N class mkdir -p .ssh

        Copy the keys to every machine (dsh doesn't help here):

for h in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
24 25 26 27 28 29 30
do scp ~/.ssh/id_dsa.pub host$d:/var/root/.ssh/authorized_keys
done

                                                Enjoy,

                                                Chris
--
Chris Pepper: <http://www.reppep.com/~pepper/>
Rockefeller University: <http://www.rockefeller.edu/>

You can use VNC to do the same thing at a fraction of the cost of Apple Remote Desktop :-)

all you need to do is run a VNC server (such as OSXvnc) on the instructor machine, and then run a VNC client (such as Chicken of the VNC) on the client. They'll need to open a session on the server machine, and can either be set up to share the mouse (so everyone can move it) or host a read-only session (so they can see stuff but don't touch).

It works relatively well, even over slow bandwiths, but if you're showing FMV (for example) then expect some form of blocking. However, if you're just demoing a program, it's great.

You can even get the students to shrink the screen so they can see both you and the normal desktop whilst they're working; useful if someone asks you a question whilst they're trying to achieve it.

If you want to force the screen, you could always SSH in and get the VNC client to connect maximised, so there's no way of switching back to other apps.

On 2/8/2005 5:04 PM, "alex_blewitt" wrote:
> You can use VNC to do the same thing at a fraction of the cost of Apple Remote
> Desktop :-)

Yes, and with a fraction of the functionality ;-)

Seriously, I love VNC and use it regularly, but to easily -- key word --
mirror your screen to every screen in a lab? With Remote Desktop you simply
select all in the main Remote Desktop window and then click the Share Screen
button. With standard VNC, *each* machine will need to manually start a
session with the main machine. If this is the type of functionality you
need, Remote Desktop is worth the cost, in my opinion, as setting it up with
standard VNC is nowhere near as easy or convenient.

On 2/8/05 7:04 PM, "alex_blewitt" <alex_blewittyahoo.com> wrote:

> You can use VNC to do the same thing at a fraction of the cost of Apple Remote
> Desktop :-)

However, you pay a lot more in setup time, and lose a lot of configuration
options that don't require screen sharing.

john

--
John C. Welch Writer/Analyst
Bynkii.com Mac and other opinions
jwelchbynkii.com

At 8:32 AM -0800 2/9/05, Dan Frakes wrote:
>On 2/8/2005 5:04 PM, "alex_blewitt" wrote:
>>You can use VNC to do the same thing at a fraction of the cost of
>>Apple Remote Desktop :-)
>
>Yes, and with a fraction of the functionality ;-)

Moreover, if just VNC is what you want, look no further than ...
Apple Remote Desktop. Version 2 uses VNC to do its screen control,
and Apple ships the best VNC *server* on the platform - its name is
Apple Remote Desktop Client. Just install the v2.1 client, and a
couple check boxes later you're hosting VNC sessions.

There's also a nifty command line utility for start/stop/config of ARD client:

/System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart

For a VNC client, ARD's Remote Desktop.app is very nice, but that's
the pay-for part of ARD. My second favorite is the UNIX TightVNC,
installed via Fink and used via X11.

--
Andrew Laurence
atlaurenuci.edu

Not meaning to cross post from one thread to another, but it seems to
me that this is directly relevant.

On Mon, 7 Feb 2005 10:44:16 -0800, Ian Hobson <ianemc2.co.uk> wrote:
> One much cheaper and simpler option I am considering for similar purpose is
>
> KMRemoteControl - available via version tracker at
> http://www.versiontracker.com/dyn/moreinfo/macosx/20771
>
> This allows you to use a keyboard/mouse on one machine as input to another
> machine via the network connection. I guess a software KM switch (no video).
> Of course, it requires you to be able to see the video of both machines.
> But, for instance, if you have your powerbook/ibook on your lap, and your
> mac mini connected to a plasma/lcd etc, you can use your laptop keyboard to
> input into the mac mini via airport as an example. I think the cost is
> around $12 for this shareware.
>
> I cannot personally vouch for it, but I have heard good things about it, and
> will be trying it as soon as I get a chance. It's not the solution for
> people who need the video switching, but it may work for others who have the
> video sorted, and also need a wireless solution (though it would work via
> ethernet as well).

Obviously I can't vouch for this product either as I've only heard of
it via TidBITS ;-) but if it works as advertised it should be pretty
trivial to set up a flash movie on each machine and then control them
with your one machine to do what you want. (Substitute web site or
keynote / local app of your choice for flash movie if you prefer.)

Christopher Appell

FreeRecruiting.com
European Market

1st solution: why not try VNC, but the other way... Set up a server on each machine, and control them all from one only client...

1st suggestion: [it might not be a solution for your actual need, but a very interesting utility I recently found: http://www.jybe.com let you show the webpage in your browser to all other people that join your session. (anyone could change the shared page so maybe unplug mice and keyboard on the others computers) it also has virtual rooms to share docs that are not on the web (seems like only MS apps by now, so powerpoint) I suppose it could work with webpages stored locally]

1st different something: use virtualPC or a new emulator which-name-I-can't-remember-right-now and try netmeeting (so old it probably runs smooth) on MS's OS or ¿GnomeMeeting? on linux

2nd (better) different something: recompile (if on OSX) any of the *n*x apps...

Don't forget to tell us what you choose and how it worked

toussaint666489spymac.com (without the figures)