Abstract: Any of an improved conventional, a refillable, or a continuous ink supply system (CISS) ink delivery apparatus, including a housing comprising one or more walls defining a chamber therein, a structural feature configured during use to detachably engage with a reciprocal receiving portion of a printer device, a fluid dispensing port extending through a first wall of the housing, and a siphon structure comprising a curved fluid-conducting conduit originating at the chamber and extending to the fluid dispensing port. Additionally and/or alternatively with respect to the siphon structure, an improved ink delivery apparatus includes any one or more of an automatically resettable chipset, a detachable cover plate and/or a fluid (gaseous and/or liquid) input port.