The earlier version is from 1968. The key thing is the format of the 'super line mark', which is the separator between the various files in the archive. The 1968 version has the following comment describing how it works: THE FORMAT OF THE 'SUPER LINE MARK' IN ARCHIV FILES IS: 777777000000K,..,..,..,777777000011K,FLN1,FLN2, $ MM/DD/YY HHMM.M $, $ZZZZZZ$,$$,$ 000$,$00 $ TOTALLING 14 WORDS, WHERE ZZZZZZ IS FILE WORD COUNT. THIS INFORMATION SHLD NOT BE KNOWN ANYWHERE IN THE PROGRAM EXCEPT IN THE FLLWING INTERNAL FUNCTIONS AND V'S STATEMENTS. This describes a #BCD format (6x 6 bit characters per 36 bit word). 5/n #CTSS #retrocomputing #IBM7094