Transparent-Mode Control Procedures for Data Communication, Using the American Standard Code for Information Interchange -A Tutorial This paper gives the considerations of Task Group X3.3.4 in the area of transparent-mode data communication control philosophy. The appearance of this paper was forecast (underthe name of "second-level control") in the earlier tutorial paper, "Control Procedures for Data Communications," Task Group document X3.3.4.44, dated May 1964. The present paper elaborates upon solutions to the problems of transparency to the basic ASCII communication control characters as outlined in the previous paper mentioned above. Moreover, it goes on to cover the additional control problems of handling material such as off line encrypted data or non-ASCII codes by means of systems providing complete character transparency. It does not cover concepts of transparency in which the normal character structure or modulation rate of a system may be abandoned. In conjunction with the earlier tutorial paper, this paper is expected to lead to a proposal for stand ardizationof data communication control procedures using the American Stand ard Code for Information Interchange. CACM April, 1965 CA650401 JB March 7, 1978 4:10 PM 1290 5 1290 1290 5 1290 1290 5 1290