There is provided a storing case adapted to be disposed on top of an amplifier, an amplifier head, or an amplifier stack. The first totem pole driver stage includes at least one PMOS pull-up transistor and at least one NMOS pull-down transistor therein that are responsive to a first pull-up signal and a first pull-down signal, respectively. A printhead and ink supply module is contained within the body and includes an elongate printhead integrated circuit which extends transverse to the path. According to another aspect, an IC includes a register corresponding to each partition to support transition fault testing. At the top of the QWIP-LED wafer an optical coupler such as a diffraction grating for coupling at least a portion of incident MFIR light into modes having an electric field component perpendicular to quantum wells of the QWIP is provided.