On Sun, Mar 25, 2018 at 6:09 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote: Now that I've poked around in the innards, I can say that this pinout has a slight mistake in it. It should be: 1. GND 2. SERIAL OUTPUT (?9 V) 3. SERIAL INPUT 4. POWER IN +5 V 5. POWER IN +5 V 6. NC 7. GND 8. NC 9. NC There are mentions here and there about how to hook up this dial box using the +5V power jack and DE9 pins 2, 3, and 7. I can confirm from direct examination that pin 7 is a ground and 8 is NC on the PCB (and that 4 and 5 are connected directly to the center pin of the 2.1mm power jack). -ethan