At 12:12 PM 7/11/2012, Richard wrote: As already mentioned, this is consistent with OS/8 date code - 3 bits of year and two of extension. You can't enter dates later than 1999: .DATE 31-DEC-99 .DATE Friday December 31, 1999 .DATE 1-JAN-00 BAD DATE .DATE 1-JAN-2000 BAD DATE What 31-DEC-99 gives you from TECO: .R TECO *^B==$$ 16375 (12 * 32) + 31) * 8 = 3320 (1999 - 1970) & 7 = 5 3325 DEC, 6375 OCT plus 4096 gives 16375. You can't tell what this really means (it could be 1983, 1991, or 1999) but that's an OS/8 failure, not TECO. -Rick

First an obvious observation. The committee which approved the bit structure for the date in RT-11 did not seem to be thinking very clearly. It is one of the few areas which are disappointing in RT-11. The 5 bits for the year should have been specified first, then the month followed finally by the day in the lowest 5 bits. Then at least until 2099, the date value would have been an obvious value - assuming a clever programmer did not steal the high order bit to save a word in some of the programs - which was done in PIP. Obviously, ALL of the operating systems will or already have problems with the date and will or already have broken the above algorithms. I think that OS/8 has already been answered. For RT-11, after 2003, those 5 year bits are reused, so the RT-11 development team finally published (around 1989) how the dates after 2003 would be kept - at least until 2099. If you understand the RT-11 value, then there are still 2 bits left in the 16 bit word for the date at the high end. Starting on January 1st, 2004, bit 14 is set and added to the 5 low order bits for the year - in bit position 5 of course - so that if bit 14 is set, 32 years are added to the low order 5 bits for the year. Starting on January 1st, 2036, bit 15 is set (bit 14 is unset) and 64 years are added to the low order 5 bits for the year. Starting on January 1st, 2068, both bits 14 and 15 will be set and 96 years are added to the low order 5 bits for the year. Naturally, the above finally breaks on January 1st, 2100 and a second word to hold the extra year bits will be required for the next 128 year cycle - or some other method will be required. There has been some discussion as to how all of the operating systems will handle dates over the next few hundred years, but thus far there does not seem to be much interest. For myself, I have proposed adding a second word to RT-11 to hold the extra year values, but nothing specific has been agreed to or even suggested by any one else except by the developer of RUST. Note that an extra word for the resident portion of RT-11 is the trivial aspect. Where the extra bits are held for file and tape directories is the critical problem. In addition, I suggest that other date and time information be supported in file directories and one of the bits in the first word (the low order bit might be best) for the status of a file label in a file structured RT-11 device) be set to note that any additional words in a file label are for the date and time of: (a) File Creation (b) File Modification (c) File Access (d) File Backup (e) Anything else that is appropriate. Note that bit 14 in that status word is already being used for the READ ONLY status and has been implemented in the RT-11 operating system since 1989 for V05.05 of RT-11. The only problem is that PIP still does not set or clear that bit and DIR does not display the status. ALSO, RUST has a problem if that bit is ever set - or so I understand - and the problem may be serious enough to cause RUST to crash. Since RT-11 seems unlikely to have another release after V05.07 except for hobby users and I have not heard from anyone else that they are considering spending the time to work on another release - unless there is some other RT-11 addict lurking that has not added their thoughts - I doubt there is anyone else who might consider spending the time on RT-11 at this point. Note that the last release in 1998 of V05.07 of RT-11 was 15 years ago which was 25 years after the first release of RT-11 in 1973 (as far as any records I have). Perhaps, on the 50 year anniversary in 10 years there could be a V05.08 for RT-11???????????????????? I have requested suggestions and a discussion for RT-11 and some co-ordination with all of the other operating systems. I request that again! Jerome Fine