The stargate in this campaign is a ring with hieroglyphs, much the same as the series. Nobody knows what the glyphs mean – they have a passing resemblance to any number of glyphs and symbols in our history, but nothing conclusive.
The stargate was easy to operate, once the scientists identified the various control and power inputs. After a few, slow, months of brute-force experimentation the scientists determined enough to quickly learn the control patters. Luckily, one of the control sequences returned a pattern that turned out to be the last address dialed. Nobody knows how the various 1s and 0s translate to light up the symbols, but they know that sending those 1s and 0s down the wire results in a dialed-up gate.
As for powering the gate, it is in many ways a massive capacitor made from super-conductive material. Nobody understands the inner workings or the material, they just know that a low charge over a long time will store-up until the gate is full, at which point it can be dialed. Under the current construction, it will take at least 6 hours to achieve the necessary charge when drawing from the mountain’s internal power supply. However, the techs have also wired-up some solar panels, so in the summertime a few days worth of charging should suffice.