Abstract: A printer cartridge includes exit and entrance arms for receiving and exiting ribbon from the cartridge in response to a drive mechanism whereby the ribbon passes from the exit arm to an entrance arm past a printhead. An oscillator is coupled to the ribbon drive mechanism and includes a cam carried by the cartridge engaging a cam lever pivotally carried by the cartridge. The lever bears against a printer support when the cartridge is disposed in the printer. When the drive mechanism advances the ribbon, the oscillator is also driven to pivot the cartridge about a longitudinal axis, thereby gradually locating upper and lower portions of the ribbon in registration with the printhead as the ribbon advances.