A dot-matrix printer is provided with different types of printheads which are interchangeably attachable to the printer carriage. The heads are provided with individual codes which are read by the printer control system and used to reconfigure its control function to suit the control requirements of...http://www.google.com.au/patents/US4872027?utm_source=gb-gplus-sharePatent US4872027 - Printer having identifiable interchangeable heads
