[prev in list] [next in list] [prev in thread] [next in thread] 

List:       vnc-list
Subject:    Re: Possible to modify VNC for screen-broadcast teaching?
From:       X-Odus <x-odus () iname ! com>
Date:       2000-05-31 23:48:07
[Download RAW message or body]

cant you just tell the server to allow connection sharing? then connect all the
student computers to the server?

David Griffiths wrote:

> Just wondering if anyone had any ideas on modifying VNC to act as a screen
> broadcaster for teaching applications.  For example, here's the situation
> I'm in:
>
> I have 25 workstations in a lab (running NT 4), and an instructor's position
> at the front of the room.  Currently we're using a dated old video projector
> which has low resolution, and isn't particularly easy to see from the back
> of the room.  For applications like teaching photoshop where small icons and
> such must be utilized, it's a real pain.
>
> Ideally, what I'd love to see (or pay for - hint hint ;P):
> ----------------------------------------------------------
> A type of VNC which could be set to broadcast from one machine (in this
> case, the instructor's machine), to a set IP range (or list of IP
> addresses).  Meanwhile, clients are running a modified viewer routine in the
> background, which is listening for an "activate" packet.
>
> The instructor hits their "send" hotkey, which transmits an "activate
> packet" which is hashed with the correct password to all of the machines in
> the range/block.
>
> When the packet is received by a client, the client program takes control of
> the student's machine (which is to say, like a screen saver, disables all
> keyboard/mouse input), and shows whatever image the instructor's server is
> broadcasting.  When the instructor finishes, they release the clients (with
> their hotkey), and the students get their individual machines back.
>
> Some considerations I see in this are:
>
> - Instructor's image sent to all computers at a high resolution, making it
> easy to see small details which are difficult to observe on an overhead.
>
> - Instructor and student machines basically run modified versions of VNC,
> and as such, cross-platform development for teaching on UNIX, Mac, Windows
> should be easy to implement.
>
> - Client machines are (optionally) locked on whatever the instructor is
> teaching at the time, preventing task switching, and mouse/keyboard inputs,
> so students can't be checking email, playing games, chatting, etc when a
> class is in session.  Ideally, two share modes could be implemented - one
> which completely locks out student access while the share is on, and the
> second which allows task switching and student input so they can follow
> along while being taught.
>
> - To get student's undivided attention, share a blank-screen to all of the
> client computers ;P
>
> - Clients should have a configurable address (or range) that they will
> accept server connections from so in the event that the server is
> compromised by students, only a set number of clients would be effected.
>
> - Hashing an activation code with a password when sent to clients, should
> help prevent troublemakers from sharing screens from their own machine and
> disrupting other students.
>
> - After a configurable network timeout (30 sec for example) without a
> broadcast packet, clients should time-out and return control of the computer
> to the student (incase the server crashes, for instance).
>
> Any thoughts, comments, offers of coding? ;P
>
> I had this thought after seeing Norton Ghost run in "broadcast ghost" mode,
> to reduce network usage.  Seems very effective.
>
> Dave.
> ---------------------------------------------------------------------
> To unsubscribe, send a message with the line: unsubscribe vnc-list
> to majordomo@uk.research.att.com
> See also: http://www.uk.research.att.com/vnc/intouch.html
> ---------------------------------------------------------------------
---------------------------------------------------------------------
To unsubscribe, send a message with the line: unsubscribe vnc-list
to majordomo@uk.research.att.com
See also: http://www.uk.research.att.com/vnc/intouch.html
---------------------------------------------------------------------

[prev in list] [next in list] [prev in thread] [next in thread]