Memory systems with a communications bus (and associated systems, devices, and methods) are disclosed herein. In one embodiment, a memory device includes an input/output terminal separate from data terminals of the memory device. The input/output terminal can be operably connected to a memory controller via a communications bus. The memory device can be configured to initiate a communication with the memory controller by outputting a signal via the input/output terminal and/or over the communications bus. The memory device can be configured to output the signal in accordance with a clock signal that is different from a second clock signal used to output or receive data signals via the data terminals. In some embodiments, the memory device is configured to initiate communications over the communication bus only when it possesses a communication token. The communication token can be transferred between memory devices operably connected to the communications bus.