serial numbers

Posted by: mschrag

serial numbers - 01/01/2002 22:36

Are serial numbers properly set and unique on everyone's Empeg? There's an interesting problem that arises if you are cloning chunks of different people's remote Empegs... Say you have three users A, B, and C. User A clones a playlist from User B. User C also clones the same playlist from User A. Now say that User A creates a new playlist that references that cloned playlist and User C copies THAT. Currently, speaking strictly about the existing Emplode, the playlist would be a reference count of 2. To pull this off properly with remote copies (and there are actually easier scenarios that this will happen with just two users -- imagine cloning playlists during multiple sessions), I need to have a globally unique FID to reference count against. I was thinking about adding a new tag on cloned files that contain FID augmented with serial number ("12345678@7E3A"). So whenever you clone a node, it would lookup that GFID in your database and know that it's an tune that you already have (albeit with a different local FID assigned).

Phew ... I know, I've made a feature unnecessarily difficult -- but it will be really cool ;) So basically, I need a number that uniquely identifies every Empeg. I'm hoping serial is it. HWaddr can be changed (my router remaps HWaddr, for instance), so I can't do that. How safe is serial for my evil needs?

Thanks
Mike
Posted by: drakino

Re: serial numbers - 02/01/2002 00:28

The serial number should be unique on every player out there. The other advantage to using it as well is that whatever you are working on would work on a Mark 1 player, whereas anything depending on the MAC address from the NIC would fail.
Posted by: mschrag

Re: serial numbers - 02/01/2002 01:06

Interesting -- didn't know that about the MAC address on Mk1's. I'm using Serial # now, so we'll see how it goes.

Thanks
Mike
Posted by: mcomb

Re: serial numbers - 02/01/2002 01:21

There are no MACs on the MK1s because they don't have ethernet. So they don't work with JEmplode anyway (maybe via serial?).

-Mike
Posted by: mschrag

Re: serial numbers - 02/01/2002 01:27

ah hah ... Explains it pretty well :) I am going to hook up jUSB on Linux and see how it works .. Actually, I wonder if javax.comm works with USB on Linux (i.e. does the Empeg appear as a serial device??). It doesn't on Windows, but Linux is a little more consistent about how that works -- I'll have to try that and see.

Mike
Posted by: altman

Re: serial numbers - 02/01/2002 02:16

Yes, they are unique. The MAC address on a mk2 is actually generated from the serial number plus the manufacturer prefix.

Hugo
Posted by: Taym

Re: serial numbers - 02/01/2002 10:07

I was thinking, is it possible to remove the limit on the clone tool that comes with emplode, and allow cloning from a higher SN to a lower one? If I am not mistaken this is not possible currently. I suppose that was due to legal reasons, or am I wrong? Now that downloads feature is possible, maybe this is too....

Thank you!
Posted by: altman

Re: serial numbers - 02/01/2002 11:25

Good point. We do have a second version of clone which works the other way round (well, a new .exe file anyway). This might be the easiest thing to release, as it doesn't require any work, just a little assembly effort (ie, replacing the .exe if you want to clone the other way).

Hugo
Posted by: Alan

Re: serial numbers - 02/01/2002 18:07

That would be nice to have, any chance of it being released any time soon?

Alan
Posted by: bonzi

Re: serial numbers - 06/01/2002 03:07

Come on, Hugo, release that 'reverse' clone tool (or did you already and I missed it?)! We have several workarounds now (including Jemplode which has more functionality in some aspects), but most non-geeks will find your tool easiest to use... (I wanted to write 'novices', but it occured to me that novices have no need for cloning tool since they just hought their *first* empeg )