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

... first pass at the main #assembly module is now done. Next step is to get it onto the emulator and start debugging.

I want to do this in a 'period correct' way, which means (virtual) #punchedcards. I think I know the 12 bit encoding which is required, although I have no idea whether that's what a real #IBM7094 would have used or whether it's just what the author of the emulator decided. Need to write a utility to convert the current ASCII encoding, which will be converted to #BCD as it's read. And I thought Windows code pages were painful!

As an aside, I was initially confused when I heard the machine used BCD, as I thought that was a numerical format where each nibble represented a single decimal digit, but it's actually a full 6-bit alphanumeric coding scheme where code points 0x00 to 0x09 (in the IBM version at least) represent the decimal digits. See https://en.wikipedia.org/wiki/BCD_(character_encoding).