Monday, 14 October 2013

Recovering data serially

Over the past few weeks I've noticed a number of posts along the lines of

we've an old XYZ machine without a network connection, can anyone help with recovering data from it?

Not having an ethernet connection is a problem, but assuming that the machine still powers ups and the disk spins, it might not be so much of a problem.

The key is to go looking to see if it has terminal application. This isn't as odd a question as a lot of computers were used to access timesharing systems back then in these pre web days, and a terminal application was fairly standard.

The good thing about terminal applications back then is that they usually incorporated a serial file transfer protocol such as xmodem, ymodem, zmodem or kermit. Of these kermit is perhaps the best, not the least because it can be put into server mode and you can push files from your host in batches.

The good news is that both lrzsz, the ?modem client for linux and ckermit are available for install on ubuntu from the repositories via apt-get.

Then all you need is a usb to 9 pin serial adapter cable and a serial nine pin null modem cable - both avaiable from ebay for a few dollars and then you should be ble to transfer data from your old machine to the new.

Yo will of course need to set up things like parity and baudrate, and it might be an idea to practice transfering data first by setting up a second linux machine and transferring data between the two - see []( for an exaple.

Despite this sounding a bit of black art, it's actually quite easy. The other good thing is that a number of embedded communications devices are still configured over a serial port, so most network technicians still know something about debugging serial connections.

Once you have a managed to establish a working connection you should then be able to get the serial communications software on your problematical machine to talk to your newly enabled serial host.

From there it's simply a matter of transferring the files across one by one and converting them to something usable - if they're wordprocessor files, LibreOffice can read most of the legacy formats and web based services like cloudconvert and zamzar can read many more ...

Written with StackEdit.

No comments: