Post #186578
2026-01-30 15:54 UTC
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
Replies (1)
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@philcowans@universeodon.com 2026-01-30 15:59
The later version is from 1970, and the comment has changed to: THE FORMAT OF 'SUPER LINE MARK' IN ASCII ARCHIV FILES IS DEFINED AS FOLLOWS: FF NL NL NL DEL DEL DEL DEL NAME1 SP SP NAME2 SP SP MM/DD/YY SP SP HHMM.M SP SP ZZZZZZ DEL DEL DEL DEL NL NL NL NL TOTALLING 14 WORDS. ZZZZZZ IS THE WORD COUNT. So by now we've switched to #ASCII. From the code, NL is what is now called LF. The code also implies that ASCII is internally represented with 9 bits (i.e. 3 octal digits), so 4 characters per 36 bit word. 6/n #CTSS #retrocomputing #IBM7094