From: utzoo!decvax!cca!hplabs!hao!menlo70!sytek!zehntel!teklabs!ucbcad!UNKNOWN:ARPAVAX:CSVAX:npois!npoiv!harpo!floyd!trb@sri-unix
Newsgroups: net.misc
Title: Re: The day that time went backwards
Article-I.D.: floyd.453
Posted: Tue Aug 17 10:24:05 1982
Received: Sun Aug 22 02:16:26 1982

Re "How many people would use a 68 year old OS?"

DEC TOPS-10 stored its date in a 12 bit field of a 36 bit word.  There
was other information in the other bits of this word.  This field was
incremented daily.  Who in the world, they thought in 1964, would be
using TOPS-10 in 1975?

In 1975, a new UUO (system call) was introduced to TOPS-10, the DATE75
UUO.  This UUO (which replaced the DATE UUO) got the date from the
original 12 bits that DATE looked at and it got another three bits from
another word in another part of the operating system tables.  Of course,
every program that wanted to know today's date had to be updated.

Live and learn.

	Andy Tannenbaum   Bell Labs  Whippany, NJ   (201) 386-6491