302 audio

Curious if the fine folks at Cambridge have ever thought about what it
would take software wise to give the user the option to select from a
variety of vario climb/sink/cruise tones. I'm not suggesting a
radical departure in the indication of the tone (increasing beeping
for climb), but the background tone that is used. I like my 302, but
I'd sure like the option for a tone that wasn't quite so harsh
Obviously the ultimate would be the ability of the owner to download
the equivalent of a ringtone for the various sounds....

Just a thought...

On Aug 25, 6:55*pm, Mark wrote:
Curious if the fine folks at Cambridge have ever thought about what it
would take software wise to give the user the option to select from a
variety of vario climb/sink/cruise tones. *I'm not suggesting a
radical departure in the indication of the tone (increasing beeping
for climb), but the background tone that is used. *I like my 302, but
I'd sure like the option for a tone that wasn't quite so harsh
Obviously the ultimate would be the ability of the owner to download
the equivalent of a ringtone for the various sounds....

Just a thought...

The fine folks at Cambridge who could have done this are now at NK.

Lets see what features the new NK Vario will have.

They really ought to be releasing specs. Won't damage their current
vario sales (NK have none) so unclear what not releasing at least
basic details gives. But not doing so certainly avoids having to deal
with annoying potential customer feedback.

Darryl

On Aug 26, 7:16*am, Darryl Ramm wrote:
On Aug 25, 6:55*pm, Mark wrote:

Curious if the fine folks at Cambridge have ever thought about what it
would take software wise to give the user the option to select from a
variety of vario climb/sink/cruise tones. *I'm not suggesting a
radical departure in the indication of the tone (increasing beeping
for climb), but the background tone that is used. *I like my 302, but
I'd sure like the option for a tone that wasn't quite so harsh
Obviously the ultimate would be the ability of the owner to download
the equivalent of a ringtone for the various sounds....

Just a thought...

The fine folks at Cambridge who could have done this are now at NK.

Lets see what features the new NK Vario will have.

They really ought to be releasing specs. Won't damage their current
vario sales (NK have none) so unclear what not releasing at least
basic details gives. But not doing so certainly avoids having to deal
with annoying potential customer feedback.

Darryl

I really enjoy my 302, but it would be great if one could have a
choice of 'ring'tones

The fine folks at Cambridge who could have done this are now at NK.


Darryl

If you are suggesting that there is no one doing software development
on the 302 at Cambridge, then perhaps they should/could consider an
open source concept...

On Thu, 26 Aug 2010 07:15:23 -0700, Darryl Ramm wrote:

Tim may have other concerns, but one problem is that secure flight
recorders use a private/public key signing mechanism (e.g. DSA). An open
source development project could not expose the private key. However I
don't see why this automatically makes this impossible in principle,
there could be schemes where a private key is held in escrow and not
disclosed even to the developers. The developers and hardware
manufactuer would also have to organize to have software releases IGC
approved.


Do you mean secure in the sense of not being able to tamper with a
signed, downloaded trace without it being easily detectable?

--
Alex

On Aug 26, 8:11*am, Alex Potter wrote:
On Thu, 26 Aug 2010 07:15:23 -0700, Darryl Ramm wrote:
Tim may have other concerns, but one problem is that secure flight
recorders use a private/public key signing mechanism (e.g. DSA). An open
source development project could not expose the private key. However I
don't see why this automatically makes this impossible in principle,
there could be schemes where a private key is held in escrow and not
disclosed even to the developers. The developers and hardware
manufactuer would also have to organize to have software releases IGC
approved.

Do you mean secure in the sense of not being able to tamper with a
signed, downloaded trace without it being easily detectable?

--
Alex

Yes. Anybody with the private key can sit at their computer make up an
entirely fake flight or edit an existing flight (e.g. take out a
restricted airspace incursion) and resign the IGC file and nobody
would be able to tell.

Darryl

Darryl

On Aug 26, 7:15*am, Darryl Ramm wrote:

The C302 has several features (e.g. use of accelerometer hardware)
that were kicked around but never shipped


I thinks it's true to say that the accelerometers were never included
in the vario function. However I'm quite sure that nomal accel is
used for the slow speed warning.


Andy (GY)

On Thu, 26 Aug 2010 08:25:25 -0700, Darryl Ramm wrote:

Yes. Anybody with the private key can sit at their computer make up an
entirely fake flight or edit an existing flight (e.g. take out a
restricted airspace incursion) and resign the IGC file and nobody would
be able to tell.


I don't think this runs as an argument. The downloaded file is, as far as
I understand it, signed by the "logger", rather than by the downloader's
computer, which makes checking for "fiddling" quite easy.

The developers can invent any key-pair they choose. The keys used in the
instrument will have been be hard-coded, therefore the private key is
already in the user's possession, even though hard, if not impossible(!?)
to read...

Potential cheats would need some considerable technical skill as well as
criminal(?) intent. Do such people fly gliders?

--
Alex

On Thu, 26 Aug 2010 19:36:11 +0100, Tim Newport-Peace wrote:

Not exactly. the Private key is held in the 302 in volatile memory that
is corrupted when the box is opened, and can only be loaded into the 302
using software only held by Cambridge. More I will not say.

Thanks for the clarification. I can understand your wish to say no more
on that subject.

Would you care to share your reasons for not opening the source code for
the logger itself? No reason nor necessity to share the key-store
mechanism, I'd have thought?


Potential cheats would need some considerable technical skill as well as
criminal(?) intent. Do such people fly gliders?

Well, yes. There well known examples of cheating attempts both in Record
Claims and World Championships.

A pity. Always one or two, I suppose.

--
Alex

On Aug 26, 1:45*am, Sven wrote:

I really enjoy my 302, but it would be great if one could have a
choice of 'ring'tones- Hide quoted text -

- Show quoted text -

Hmmmm . . . perhaps some of that Meg Ryan sound track for lift?? :c)

for those who don't remember, http://www.youtube.com/watch?v=5nNhOH4Y0bI

bumper
zz
Quiet Vent and MKIV "high tech" yaw string