UP Core specifications - UP Bridge the Gap,GXAXX0800_Ethernet/RS485 IO_Distributed IO_Modem_,What does this schematic symbol mean (rectangle with two tails, ,GXAXX0800_Ethernet/RS485 IO_Distributed IO_Modem_,Need help with obscure Fujitsu board. PCIe 2.0 doesn't work. Only PCIe 1.0. Details in the comments. : r/homelab