They are very useful. I used one (an old nokia cable that had been hacked apart) a few years back to get a serial console on my WD Sharespace, so I could figur

They are very useful. I used one (an old nokia cable that had been hacked apart) a few years back to get a serial console on my WD Sharespace, so I could figure out how I was going to get debian running on there, interact with the bootloader etc. It was a fun project. Start with the multimeter, probe for some pins that look like they might be around the right voltages. Next, if you have shell access, cat some data down the port and see if what you think is the TX pin starts to look more alive, then attach your dongle to the likely-looking pins and away you go...