Operating systems of the 1970s handling dates beyond the year 2000

John Wilson wilson at dbit.com
Mon Jan 19 11:10:33 CST 2015

On Mon, Jan 19, 2015 at 02:03:42PM +0100, Johnny Billquist wrote:
>I don't know what is special about 1972. I always assumed they used
>that base because that's the year RSTS-11 first showed up.

Actually it's 1970 (but RT-11 uses 1972), and it's inherited from DOS/BATCH
which I think everyone knew was a stopgap, like most systems at the time ...
so it didn't plan ahead very well, even enough to multiply by 366. instead
of 1000.  But yeah 1970 is pretty much the beginning of time as far as
PDP-11s in general (including DOS/BATCH) are concerned.  At least this shows
more foresight than OS/8!  I think at the time the culture really must
have been that computer architectures have a lifespan well under a decade,
just because that had largely been true so far.  The S/360 was an anomaly.

John Wilson
D Bit

More information about the cctalk mailing list