Ok, this question is only sort of related to the HP 3000.  I'm writing some
64 bit unsigned math routines for the classic systems to total network
statistics for a world-wide network, and using my HP 16C calculator to check
my results.  Here is my problem.
 
Three times in three days (once a day) my HP 16C has "locked up" after doing
a number of 64 bit unsigned operations and then switching to floating point.
I can't identify any specific series of 64 bit operations that lead up to
the failure, but the final steps are always the same (as is the resulting
lockup).  Those steps are:
 
Keypresses:
   DEC    (return to decimal display mode)
   0
   ENTER  (put a zero on TOS)
   f      (function prefix)
   FLOAT  (function is switch to floating point mode)
   2      (2 decimal digits)
   1
   2
   3
   ENTER  (the numbers don't matter, enter any number followed by ENTER)
   4
   5
   6
   ?      (any second number followed by any operator)
Calculator locks up.  All keys except "A" and "GSB" are completely ignored
(no change in display at all).  When "A" or "GSB" keys are pressed, display
blinks once.
 
Also, the "ON" button does not function (can't turn calculator off).  The
calculator's automatic powerdown doesn't function either.  I tried removing
the batteries for five minutes (several times) and pressing keys (or not
pressing keys) while the batteries were removed.  The result is always the
same - calculator display off, calculator does not respond to any keys.
 
However, the calculator can be completely reset by removing the batteries
and leaving the batteries out of the calculator overnight.  When the
batteries are replaced in the morning, the calculator displays one of:
 
   dF
or:
   PF
 
which can be reset by entering:
  0
  ENTER
 
I've given the calculator a workout doing 8 bit, 16 bit, 32 bit, and
floating point operations yesterday and today, and it won't fail unless I do
a LOT (20 or 30 minutes straight) of 64 bit unsigned operations.
 
Anyone heard of such a thing?  Anyone know of a "bug" list for the 16C?  Any
suggestions (other than "don't do 64 bit unsigned operations")?
 
...or is my 16C just getting flakey after 12 years?
 
John
--------------------------------------------------------------
John Korb                            email: [log in to unmask]
Innovative Software Solutions, Inc.
 
The thoughts, comments, and opinions expressed herein are mine
and do not reflect those of my employer(s), or anyone else.