longitudinal positioning of the cartridge 11 on the baseplate 12 39 in order to put the ribbon 13 wound on the takeup spool 16 into operative engageent with the rotatable drive member 18 the keyslots 33 are aligned with the longitudinal axis of the baseplate 12 39 to permit the sliding movement of the cartridge 11 longitudinally toward the rotatable drive member 18 the rotatable drive member 18 is mounted on the baseplate 12 39 of printer 60 to rotate about an axis perpendicular to the plane of the baseplate 12 39 it is driven and powered by external means such as a motor carried by the printer 60 and located below the baseplate 12 39 and controlled by suitable controls such as a switch a portion 18 39 fig6 of the rotatable drive member 18 extends through the baseplate 12 39 the rotatable drive member 18 indirectly drives the takeup spool 16 by directly engaging the ribbon 13 under suitable pressure as seen in fig1 the cartridge housing 17 in this embodiment further includes an elongated aperture or slot 40 which extends along the longitudinal axis of the housing 17 and contiguously through the sidewall 23 and the bottomwall 22.