Welcome to part 3 in this series of setting up the gd-77. If you want to know more, search for the radioddity gd-77 on amazon. We set up a code plug, which is like a list of repeaters for the radio. You can set up analog and digital repeaters here. If you want to know more about the guys that did the firmware for this radio go to spensorweb.net and click the gd-77 link.