[Info-vax] VMS process communication

[Steven Schweda]

> I tire of hearing about people calculating Pi to billions of digits.
> What good does that do? 

   Recreation?  Challenge?  Benchmark?  (And I thought that _I_ was a
whiner.)

   My quick search on this new Inter-Web thing for "pi many digits"
found (among many other things):

      https://cloud.google.com/blog/products/compute/calculating-100-trillion-digits-of-pi-on-google-cloud

(No surprise, perhaps, that that was first in the Google search
results.)

   I seem to have found a pi-calculating program in 1999, and run it on
a few of my systems then.  Comparing the output for a million digits
(give or take) on a VAXstation 2000 (VMS V5.5-2) and a more recent run
on a Mac Pro (Late 2013)/VMware (VMS E9.2):

v87 $ diff 1048576_DIGITS_OF_PI_B_WEAK 1048576_DIGITS_OF_PI_B_V87
************
File V87$DKA0:[SMS.PI]1048576_DIGITS_OF_PI_B_WEAK.;1
24123   Total Execution time: 113515.44 Seconds
24124   
******
File V87$DKA0:[SMS.PI]1048576_DIGITS_OF_PI_B_V87.;1
24123   Total Execution time:  11.38 Seconds
24124   
************

Of course, the x86_64 results might suffer from the sub-optimal cross
(C) compiler.


> Looks correct but NASA doesn't use more than [...]

   Same search, further down:

      https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimals-of-pi-do-we-really-need/