An inkjet print cartridge (10) comprises a substrate (28) having a plurality of ink firing chambers (130) along a top surface of said substrate and a first outer edge (86) in close proximity to the ink firing chambers. The ink firing chambers are arranged in first and second arrays and with the firing chambers spaced so as to provide 600 dots per inch printing. An ink channel connects an ink reservoir with the chambers, and include a primary channel (52) connected to the reservoir and to a secondary channel. The primary channel (52) allows ink to flow from the reservoir, around the first outer edge to the secondary channel so as to be proximate to the ink firing chambers. A separate inlet passage (132) for each chamber connects the secondary channel with the chamber for allowing high frequency refill. A group of firing chambers in adjacent relationship forms a primitive (P1-P14) in which only one chamber is activated at a time. A circuit (78) on the substrate connects to the firing elements, while a second circuit (36) on the cartridge connects to the first circuit means, for transmitting firing signals to ink firing elements at a frequency greater than 9 kHz.