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From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: RTC (Was: Multi-tasking and OS books)
Message-ID: <6906@cbmvax.UUCP>
Date: 17 May 89 20:22:29 GMT
References: <5853@cs.Buffalo.EDU>
Organization: Commodore Technology, West Chester, PA
Lines: 19

in article <5853@cs.Buffalo.EDU>, ugkamins@sunybcs.uucp (John Kaminski) says:
> Quote: I hate long references lists.

> Also, consider that the PC and the PC XT had no standard real time clock, 
> and all those dates and times in the directory listing are derived from the 
> user entering the date/time at boot time and that aforemetioned (sp?) interrupt 
> clock.

That's pretty standard.  Most RTC clocks are, at best, quirky.  They often take
long times to read, vs. normal I/O ports, and some actually lose time when read.
Most systems I've encountered, including PClones, Amigas, even C64s, have an 
interrupt-based system clock that's set on powerup from an RTC if one exists.
This also has the advantage of making it possible to deliver a working system
with no RTC.  The RTC function is handy, but optional.  The system's knowledge 
of real and elapsed time is usually critical -- even the C64 needed this.
-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
              Amiga -- It's not just a job, it's an obsession