VNC?

[A. Jorge Garcia]

I just figured out that VNC is included in KNOPPIX! This sounds very interesting. I'm curious how people are using VNC in KNOPPIX and how successful you've been.

I was playing with <K><System><Desktop Sharing> and <K><Internet><Remote Desktop Connection> to get 2 players on one xboard from 2 PCs. I seemed to be able to remotely connect to one PC's desktop from another whereby both users have keyboard/mouse control of the same desktop. I get as far a clicking <K> remotely to try to start an xboard game and then the connection times-out....

TIA,
AJG

[firebyrd10]

I have a VNC server on an old computer that I bought of ebay to play old games with. It didn't come with a monitor and its a hassle to switch mine to it. So I just boot it up then connect to it via VNC.

for me VNC doesn't handle full screen programs and always locks up on me but its great for just about everything else.

[ktheking]

I'm using VNC already 4 years. (under windoze).
But now with the latest knoppix releases it really rocks.

VNC can now be installed as a service on MS pc's.
This means from within the company a remote connection system hosted by RSA-server is in place ,to perform safe connection.
On top of that is a VPN tunneling in place based on CISCO.

Well, from my knoppix anywhere on the net I can do a connection trough my router at home (using IPSEC for VPN) using the VPN cisco client present on the knoppix cd . And connect then with VNC to my MS desktop in order to work.
So on the job I can have a powerfull pc for running all sorts of apps.
And at home I take on old pentium without harddisk and so on (just enough to run knoppix KDE).
And voila,

For a cheap price I got teleworking at home running apps at a good speed.

Damn .. it reminds me more and more of terminal-server enviroments like in the old days ;-) ...

[c123]

As well as KDE's desktop sharing/remote desktop connection, you can use the Debian TightVNC package.

KDE's VNC is nice in that you can view/share display:0, but I haven't yet figured out how to manaully set a connection window of more than an hour nor how to set the password to one of my choosing :(

For the above reasons I often just use the Debian TightVNC binaries...

[A. Jorge Garcia]

firebyrd10: I'm confused, you say that VNC locks up on full-screen apps but is fine for everything else. I thought VNC was intended for such apps! What do you mean by everything else?

ktheking: You say that ever since the latest KNOPPIX release, VNC rocks! Does that mean that earlier releases had bugs in VNC? I've been using a 2003.1119 debian hdinstall ever since that ISO came out with no need to upgrade until perhaps now. Do you recommend that I upgrade to the latest ISO?

c123: OK, so what I'm using is a KDE version of VNC, not true VNC? You recommend I try the Debian TightVNC binaries. Can I install this with apt-get? Also, do I understand you correctly: TightVNC makes it easy to set the timeout and the password? What if I want to take control of a student's desktop remotely (from mine), can I do this without his/her permission maybe as root?

Thanx for all your input gentlemen, this is sounding more and more promising all the time!

TIA,
AJG

[firebyrd10]

What I'm taking about is more or less games that take control of the entire screen not apps that enlarge to cover the entire screen (get it?)

As for useing a differnt VNC program I use RealVNC. Unlike desktop sharing it never times out and you can set passwords.

Only problem is you can't share display :0 (the one that basic users use)

However you can do cross system controls (windows to linux, linux to windows, etc) which I don't think you can do with Desktop sharing. ANd yes, you could take control of a student PC without there permission.

But I think that RealVNC's beta version is useing a hack to let it display :0

As long as on the topic what is the 0 and the .0 in :0.0 IN detail please

[c123]

c123: OK, so what I'm using is a KDE version of VNC, not true VNC? You recommend I try the Debian TightVNC binaries. Can I install this with apt-get? Also, do I understand you correctly: TightVNC makes it easy to set the timeout and the password? What if I want to take control of a student's desktop remotely (from mine), can I do this without his/her permission maybe as root?

Thanx for all your input gentlemen, this is sounding more and more promising all the time!

TIA,
AJG
VNC was originally developed in the Olivetti research labs in the UK. The original developers stopped working on it at one stage. Then a few differnent groups of developers continued development (VNC is open-source), this led to several versions including TridiaVNC and TightVNC. Then the original developers started doing VNC again, this time under the new name 'RealVNC'. So what I'm saying is that there is no longer a 'true' VNC, just several different variants (which are still inter-operable BTW).

Personally and in general, for multi OS environments, I'd suggest using TightVNC or RealVNC. I like TightVNC (good compression schemes), but I'm also looking at the betas of the new RealVNC version (very promising). I subscribe to both mailing lists.

For a standard KDE (Knoppix) user , KDE desktop sharing is good as it's a KDE app and it allows you to see display:0. With other versions of VNC you generally cannot (without an xserver hack) see display:0. Display:0 is the one that the current user is looking at. I.e. with most VNC versions on Linux you cannot really share a desktop :(

However there are two limitations to KDE desktop sharing that annoy me - the fact you cannot set the password, and that the connection window is 1 hour only (i.e. if you do not connect within the hour, the invitation is no longer valid - you can no longer connect). Also KDE desktop sharing uses version 3.5 of the RFB (VNC) protocol, whereas Tight uses version 3.7 (better compression).

As firebyrd10 said, RealVNC 4 (currently in beta) will allow you to see the same desktop (display:0). I imagine TightVNC will allow you to do the same soon after (the different developers will implement good ideas from other groups).

You'll be glad to know that TightVNC is already in Knoppix :) It's more or less a case of setting a password for the user, then typing 'vncserver' to start it up (man vncserver for switches).

Anyway thuis post is starting to ramble ;), and I have work to do :( Check out the Real and Tight sites ( www.realvnc.com and www.tightvnc.com)

As for your question about seeing your students' desktop, what OS will your students be running (I think debian/Knoppix,)?

p.s. KDE's Desktop sharing is "cross platform" - i.e. from my windows box I've been able to see my KDE desktop and vice versa. VNC (and its variants) are designed to be closs platform - a viewer does not care what platform the server is on and vice versa.

[A. Jorge Garcia]

Oh! vncserver and vncviewer are already in KNOPPIX? OK, that's good to know. I just apt-get installed tightvncserver and xvncviewer (which came up in apt-cache search vnc) on two of my hdinstalls last night to play with vnc. Well, now I don't have to install anything on my 25 other PCs in the LAN!

BTW, I use KNOPPIX and my students use KNOPPIX, so cross-platform is nice but not an issue.

Thanx,
AJG

[j.drake]

AJ, from your post and your avatar, it sounds like you may be just the person to ask about chess variants. I've been playing Tori Shogi on Steve Evans' Shogi Variants program for a while, and long ago discovered how limited its play logic is (interface is good, though). Generally, I can capture all pieces and mate without dropping or promoting any cranes or falcons in 5 minutes or less. Any ideas?

Sorry for the hijack, but it seemed a great opportunity. Just step over me if you want - I won't mind. And if you prefer to post a reply in the lounge, I'll look there too.. Thanks

[c123]

Oh! vncserver and vncviewer are already in KNOPPIX? OK, that's good to know. I just apt-get installed tightvncserver and xvncviewer (which came up in apt-cache search vnc) on two of my hdinstalls last night to play with vnc. Well, now I don't have to install anything on my 25 other PCs in the LAN!

BTW, I use KNOPPIX and my students use KNOPPIX, so cross-platform is nice but not an issue.

Thanx,
AJG
How do your students start up Knoppix? CD/HDD? If CD, is it custom?

If your students are using the standard CD, then you are best to use KDE desktop sharing (actually it's your only option). Your students will have to start the server (using the 'Desktop Sharing' item in the menu) and will then have to tell you the password (and possibily their IP address) either by e-mail or vocally. Your students will also be able to decide if you can control their desktop or not (by default you can only view the desktop).

Voila, HTH.

[firebyrd10]

I've never gotten desktop sharing to work cross platform......

oh well I installed Real VNC anyway.

[A. Jorge Garcia]

j.drake: Sorry to let you down, but I'm not big on variants. I have no idea what Steve Evan's Shogi or cranes are! The only chess variants I've tried are BugHouse and FischerRandom.

Maybe you can help me. I'm looking for a linux client where two people can play standard chess over a LAN real-time with a clock. I tried xboard, but it only lets you play a chess engine or other people or FICS. I tried eboard which adds P2P play, but its buggy and crashes alot. Now I'm trying VNC with xboard and this works fine, except that you only get a chess clock when playing an engine or FICS.... I'm a bit frustrated, maybe you can tell?

c123: We have a classroom LAN of 25 PCs all running KNOPPIX from hdd (knoppix-installer as debian 20031119). One PC is set up as the print server and file server where my students login remotely and save their work via X server or sshd. Does that make a difference?

TIA,
AJG

[j.drake]

OK, thanks, AJ. I used to work in an office with the biggest chess dork I've ever met. He was always looking for people to play chess with, except that he really loved the asian variants. I was one of the few people who consented to be taught. Now I'm hooked too. Unfortunately, he moved away to parts unknown, and I'm probably one of the few people in Texas who know what Shogi (Japanese chess) or Xiang Qi (Chinese chess) are, much less how to play them (well, OK, there is his ex-wife, but that would be rather awkward now, wouldn't it)? So, I play against the computer, which I prefer anyway. Steve Evans wrote a freeware program for W$ with most of the Shogi variants built in. It's a great interface, but has a weak engine.

http://trout.customer.netspace.net.au/

Anyway, just so you won't think I was speaking gibberish, tori shogi (bird chess) is my favorite, and the various pieces are named after birds (phoenix =king, eagle, falcon, crane, etc.). The cool thing about shogi (most variants, anyway) is that when you capture an opposing piece, you can "drop" it on the board as your own piece in any location (for the most part) you choose. The pieces are not colored; they are arrow-shaped flat tiles, and you can tell whose piece is whose by the direction the arrowhead is pointing (IOW, my pieces would point toward you, and vice versa). The other unique thing about most variants of shogi is that the pieces are able to promote if they penetrate deeply enough into the opponent's territory. Promotion is indicated by turning the tile over.

Cannot help you with the linux stuff. I am still a newbie, and I'm holding back waiting for the interface to develop a bit more (e.g., ability to work with NTFS - I'm hoping the Knoppix 3.4, when it's released will take care of that, and I'm also waiting for a better interface to facilitate DVD burning)..

[A. Jorge Garcia]

OK, asian chess, now I understand!

You know, that must be where BugHouse came from. In BugHouse you play in teams of 2 against 2 (4 chess boards). If you're playing White, your teammate is playing Black. So, when you capture a Black peice you give it to your teammate who may place it on his board (and visa-versa).

Regards,
AJG

[c123]

c123: We have a classroom LAN of 25 PCs all running KNOPPIX from hdd (knoppix-installer as debian 20031119). One PC is set up as the print server and file server where my students login remotely and save their work via X server or sshd. Does that make a difference?

TIA,
AJG
Do you want to see your students' desktops, or do you want to show them yours? Desktop Sharing does not seem to be working (according to a few quick tests this evening and a bug report on the KDE site) in KDE 3.2.1, but I remember it working fine in the version of Knoppix you are using (I had it installed at one time).

If you are interested in seeing your students' desktops, do you want your students to have to "invite you" or do you want to be able to see their desktop at any moment?

[A. Jorge Garcia]

I'd like to be able to see their desktop whenever I want. Also, it would be nice if they could see mine when I wanted as well. BTW, I can't seem to get KDE desktop sharing to work on this version of KNOPPIX either. It timesout too soon and I don't see a way to change the timeout....

Thanx,
AJG

[c123]

when I had it working with the version you have installed, I had a mixed network (one knoppix and one windows machine). Never tried it with two knoppix machines (would like to, but I doubt I'll get the time).

an alternative to KDE Desktop Sharing is to use the latest beta of RealVNC 4.0 which has the capability of sharing a desktop. To do this though, you would need to install it on every machine... I've no idea how you auto-update 15-30 Debian desptops at a time :( (a case of building your own .deb and getting your students to install the package in class?)

Once installed, you would set up the VNC server with a passowrd, and then (I imagine) write a script so that VNC is started each time X is started (such scripts can be found googling). You would need to find a way to stop your students from killing VNC (saying that I don't know if they would be able to kill VNC without killing X at the same time...).

I'd like to help you out more, but I don't have that much time and I'm too inexeperienced I'm afraid. What I would suggest though is subscribing to the RealVNC mailing list (I get the digest), and checking out the archives. Haven't been able to read the digests for a while now, but I remember VNC class-room questions popping up quite regularly.

If I see anything/try anything, I'll post here and/or PM you.

Have fun!

[c123]

The developer in charge of 'Desktop Sharing' has fixed the bug, it will be in KDE 3.2.2 (available sometime this month I get the impression)

http://bugs.kde.org/show_bug.cgi?id=77412

WRT RealVNC 4.0b4 (that I refer to in anothe rpost), I think I know the problem now (good old RealVNC mailing list) and will try the suggested solution tonight.

[A. Jorge Garcia]

The bug you refer is accessing display :0?

TIA,
AJG

[c123]

Yes. [edit] Let me qualify that - the bug is with KDE Desktop Sharing in KDE 3.2.1, and Desktop Sharing *is* sharing the (root) display :0.

BTW got RealVNC 4.0b4 working a couple of weeks ago, very nice :)

[ instructions are in another thread in installs ]