Re: [MacPerl] Y2K complience

[John W Baxter <jwblist@olympus.net>]

At 15:19 -0400 6/18/97, Gary Ebert wrote:
>Also I find it hard to believe that the epoch on a Mac is January 1,
>1904.  I am not a mac expert (I work mainly on unix boxes) but I find it
>hard to believe that _all_ macs can store a number that large!  Just to
>get to the year 2000 we would be talking about 96 years (that is
>2,936,217,600 seconds).  That would fit into a 32 bit binary number with
>about 43 years to spare.  But I do not believe that the 68k macs are 32
>bit machines.  Maybe the epoch is Jan 1, 1904 on PowerPC's but not on
>68k mac's but I very much doubt it.  That would make for very very
>unportable code!!!!

Believe.  The Mac epoch is Jan 1, 1904, and the Mac clock is 32 bits (in
many languages, the clock has been negative since 1972 or so, which causes
occasional consternation but few real problems).  The more modern Mac
system software takes the 32-bit clock and puts it into a 64-bit signed
value (good for roughly 1904 +/- 33,000 years).

All 680x0 chips do 32 bit integer arithmetic...the data path into and out
of the older ones (68000) is 16 bits wide (that's what led to the naming of
the pre-Macintosh (and non-Apple) "Fortune 16/32").

  --John

--
John Baxter (Born before ENIAC, but not by much.)
   jwblist@olympus.net      Port Ludlow, WA, USA



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