Does anyone have procedures or documentation of retreiving messages from a digital answering machine?
The only connection to the decive is thru a rj11 phone jack.
just an update for anyone who viewed my original request.
This device had to be sent off to the FBI for further investigation.
I would still love to know what they are using or procedures.
Keeping this thread alive….
I too would like to retrieve deleted voice messages from a Panasonic KXTG6071 answering machine.
Maybe no one person has the complete solution, but maybe you know the file format? file system? access method? storage chip? over-write algorithm? a friend who knows a friend who's sisters dad is an engineer for an answering machine maker?
I can't speak to that specific model but many modern answering machines use NVRAM or simple RAM (with battery backup) to store messages, typically in one of the standard digital audio encoding formats and with a very simple file system. That is because the vendors don't want to write an entire OS just to make an answering machine. Thus, what you typically see is a stripped down OS (such as Linux or OS/2), a simple file system, and a simple application which runs as a service and takes care of recording the messages.
If you know the file system you can figure out the format for the messages. In my experience, which I admit is limited because, frankly, not too many of my clients have been interested in this, deleted messages are not overwritten but treated the same as deleted files and recoverable with the right technology.
Doing a forensic copy is not hard assuming that you have the appropriate ROM burner but unless you are a chip testing shop, you probably aren't equipped to handle every variation out there.
I've done a couple of these and each one has been different but as long as you have the right tools and patience, it isn't that hard.
But as far as I know, there is no general purpose acquisition tool which will work for all answering machines, so you have to pull the system apart to see what you need to image it.
In most of the cases (civil) that I've seen where this is an issue, the expense of the forensic analysis outweighs the perceived benefits.
I own an AT&T 1856 Digital Answering System Home Machine attached to a standard j11 wall jack and sharing a split line with my laptop (filter on line). I wish to recover a series of messages which were unexpectedly lost about February 1 of this year (I did not press the DELETE button on the joystick; I have no voicemail involvement with the service provider, Verizon). The unit is approximately eight years old, and it features Erasure-Prevention in the event of power outage. All functions operate as designed; no sign of internal trouble with the machine. Any suggestions as to whom I should physically take the unit to for testing/disassembly?  ThomasVictory51@gmail.com