RFC 338 (rfc338) - Page 2 of 6


EBCDIC/ASCII Mapping for Network RJE



Alternative Format: Original Text Document



RFC 338           EBCDIC/ASCII MAPPING FOR NETWORK RJE          May 1972


   special-purpose text composition programs, IBM 360 programs use only
   the 89 "basic" EBCDIC graphics [5] shown in RFC #183 as well as in
   Figure 1.  An IBM 029 "EBCDIC" keypunch can create 63 graphics: the
   89 basic EBCDIC graphics less the 26 lower case letters.  In fact,
   OS/360 requires an even smaller subset of EBCDIC, 60 characters
   commonly called the "PL/1 character set".  The PL/1 set consists of
   the 89 basic graphics, less the 26 lower case letters as well as the
   three graphics !" (cent sign, exclamation point, and
   quotation).

C. CHARACTER MAPPING IN NETRJS

   We consider now the requirements of a ASCII/EBCDIC mapping for NETRJS
   or any rje protocol.  These requirements are as follows:

      Efficiency:

      The translation should be character-to-character, so that the CPU
      operation "translate" can be used and character scans obviated.
      This is important because a significant volume of character data
      may be moved during rje operations.

      Usability:

      (1) All of the 89 EBCDIC graphics should be mapped into
          corresponding ASCII characters.

      (2) The mapping should be as nearly transparent as possible, i.e.,
          whenever the same graphic appears in both sets, it should map
          onto itself.

      (3) To minimize the adaptation required of an EBCDIC-oriented
          programmer, the ASCII graphics should evoke the corresponding
          EBCDIC graphic, when they are not identical.

   Theses considerations led us to incorporate Winett's rules II (a) and
   III (b) (see page 4 of the RFC #183) into NETRJS:


        ASCII                EBCDIC
        -----                ------
          |                     |

          ~                 

          \                 





Braden