|HP 41cx, CLONIX, cosmic rays? Northern lights? what gives?|
Message #1 Posted by Geoff Quickfall on 13 Oct 2008, 5:54 p.m.
I was on my way to London, currently at 35,000' in the cockpit over Greenland. I was looking forward to the HPCC meeting at Imperial College which I try to make every second Saturday of the month. I was demonstrating the capabilities of the HP41CX I had:
The current configuration is a double X memory followed by a Clonix and then an IR module for printing. I also carry an infared printer and card reader with a 'wall' of cards.
The double x memory contains 423 registers of program and data files while the program registers contain the programs associated with the key overlay you see in the picture above.
While I was demonstrating the calculator I placed it on the communications panel separating the two pilots seats. This panel, pictured here:
is backlit with incandescant bulbs and generates heat. I refer to the position just forward of the thrust levers where the paper can be seen. Placing the calculator on the panel will cause the calculator to warm but only slightly.
Now that the background has been set let me tell you what happened!
I had turned it on and was explaining the functions and modules etc. to a fellow pilot when the calculator started to warm up and the battery enunciator came on. I thought it odd that the batteries would be low as they were new. At the time, the heat I thought was transfer from the panel described. As I continued to demonstrate, all functions and modules working correctly the calc got warmer still.
At this point I got alarmed, turned it off and it continued to get even hotter. I removed the battery pack and then each module which included the CLONIX, Double X memory, and IR. I then cooled the whole package down with an air vent. I left the calc for an hour as other duties occurred.
On my break period I reinserted the battery pack with out the modules into the calc. All functions were perfect. I then introduced the double x memory and to my surprise it had maintained the data and program files without any loss! After installing and removing each module sequentially and testing the calculator, I then inserted all the modules and started the calculator. It functioned perfectly with no loss of any memory or damage to the virtual memory. I could not duplicate the failure.
The CLONIX module however, received physical, but not internal damage in the form of a heat distorted module case.
Also a faint smell of burnt marshmallows emanated from the opening of the module.
As I stated, the calculator works perfectly and the only result was the to the Clonix module case. The internal volatile memory of the Calculator, Double x memory, Ir module nor the CLONIX were disturbed in any way.
It was postulated at the HPCC meeting in London this Saturday that it may have been a stray cosmic ray interacting with a thyristor (spelling?) in the calculator creating an 'on' loop or short.
I guess I was just lucky that I did not leave it on the console running without checking!
Interesting story, I think, and to see physical heat damage to the CLONIX module with no disruption of the internal components is quite remarkable.
If Diego is reading this, it is a testament to his CLONIX that although it recieved enough heat to damage the module case, the circuitry in the module survived intact! It uploads and downloads through the pic programmer to the PC and functions perfectly in the calc. Still fits too!
Any other explanations are welcome.....