[Avernar]

> It is also worth noting that earth in the show built their own DHD which presumably would have different computer limitations than the ancient built DHD

The gate itself has control crystals as you can dial out without a DHD if you just give it power and some elbow grease. The 38 minute cutoff is probably in that code.

They must have run out of code space in the gate and had to offload some of the code to the DHD. :D The correlative update routine for the coordinate system is in the DHD for example so the earth gate could originally only dial Abydos until they added that to their homebrew DHD.