and outlet manifolds 48 and 50 respectively sheets of media are fed through the print engine by the main drive roller 186 and the exit feed roller 178 the main drive roller 186 is driven by the main drive pulley and encoder disk 188 the exit feed roller 178 is driven by the exit drive pulley 180 which is synchronized to the main drive pulley 188 by the media feed belt 182 the main drive pulley 188 is powered by the media feed motor 190 via the input drive belt 192 the main drive pulley 188 has an encoder disk which is read by the drive pulley sensor 184 data relating to the speed and number of revolutions of the drive shafts 186 and 178 is sent to the print engine controller or pec the pec not shown is mounted to the main pcb 194 printed circuit board and is the primary micro processor for controlling the operation of the printer fig2 b shows the print engine 3 with the printhead cartridge removed to reveal the apertures 122 in each of the sockets 120 each aperture 122 receives one of the spouts 52 see fig5 on the inlet and outlet manifolds as discussed above the ink tanks have an arbitrary position and configuration but simply connect to hollow spigots 124 see fig8 at the rear of the sockets 120 in the inlet coupling the spigot 124 at the rear of the outlet coupling leads to the waste ink outlet in the sump 18 see fig1 reinforced bearing surfaces 128 are fixed to the pressed metal casing 196 of the print engine 3 these provide reference points for locating the printhead cartridge within the print engine they are also positioned to provide a bearing.