1463	 More on Extensible Machines	 One of the most salient characteristics of extensible machines EM is the facility for providing system control over program-to-program and program-to-data linkage e.g. address connection . It is the intent of this paper to expand and clarify the remarks concerning program-to-program and program-to-data linkage that were embodied in the authors previous paper on the EM concepts and to finally trace the employment of linkage mechanisms through various levels of programming languages.
