RFC 385 (rfc385) - Page 4 of 8
Comments on the File Transfer Protocol
Alternative Format: Original Text Document
NWG/RFC 385 Page 2 ASCII with ASA vertical format Control - This is the "Print file-ASCII" defined in RFC 354. The server is to transform the data in accordance with ASA (Fortran) vertical format control procedures for printing on printers that still use this standard. The data is to be transferred as 8-bit bytes. EBCDIC with ASA vertical format control - This is the EBCDIC Print File defined in RFC 354. The server is to transform the data in accordance with ASA (Fortran) vertical format control standards but using the EBCDIC character code. The data is to be transferred in 8-bit bytes. The new types are to be denoted by symbols E for EBCDIC, P for Print file-ASCII and F for Formatted (ASA standard) EBCDIC print file. A discussion of the ASA vertical format control appears in NWG/RFC 189, Appendix C, and in Communications of the ACM, Vol 7, No. 10, p. 606, October 1964. According to the ASA vertical format control standards, the first character of a formatted record is not printed but determines vertical spacing as follows: Character Vertical Spacing before printing --------- -------------------------------- Blank One line 0 Two lines 1 To first line of next page + No advance In addition to the above four, there are more characters (defined in Appendix C, RFC 189) which represent an IBM extension to the ASA standard. 4. A comparison of "stream" and "text" modes is in order. The advantages of "stream" mode are: 1) The receiver need not scan the incoming bytes. 2) It is usable with all data types. The disadvantages are: 1) The EOF by closing the connection is not reliable. 2) The EOR by ASCII _CRLF_ is unreliable as the _CRLF_ really may be valid data rather than an EOR. It is an EOR only if the sender and receiver have a _prior_ agreement to that effect.