[TriLUG] thermal evaluation of cpu

[Rick DeNatale]

On 3/16/06, John Mitchell <john280z at gmail.com> wrote:

>    Can the Trilug suggest any other cpu intensive programs?

How about a simple infinite loop, can't get more cpu intensive than that! <G>

>From the oldy moldy department, one of the most run programs on the
IBM/360 was the utility called IEFBR14.  IEFBR14 was a "noop" program
which was used for a job or jobstep in which the useful work could be
done completely with JCL statements, like allocating or deleting
files. IEF was the prefix for IBM utility programs.  The BR14 part
came from the assembler code which was simply*:

     BR 14

or branch the the address in register 14, which under 360 calling
conventions was the return address from a subroutine.  I remember that
we got a laugh when one of the system programmers at the UConn
computer center decided to write another utility and called it
IEFBR15, only because it was "one more."  The laugh was because
register 15 was used to contain the address of the entry point of a
subroutine.

*Well it was just that at first.  A bug report was filed against
IEFBR14 was that it wasn't clearing the register which contained the
return code of the subroutine.  This made it the program with the
highest ratio of bugs to lines of code.

--
Rick DeNatale

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