|Re: Unrecoverable crash to lock-up|
Message #12 Posted by John Wasilewski on 2 Oct 2007, 4:06 p.m.,
in response to message #11 by Seth Morabito
Thank you Seth.
I have just sent the following message by email:
date 2 Oct 2007 21:03
subject HP 35s unrecoverable crash problem
HP 35s Scientific calculator
Serial no. CNA72100255
Someone on the HP calculators users' forum at www.hpmuseum.org has suggested that I write to you about what may be a very serious fault with the seemingly excellent HP35s. I'm told you will certainly want to know about this.
I short, I may have discovered a system instability causing occasional unrecoverable crashes, under as-yet unknown circumstances. The gravity of this comes from the fact that, with no means of saving programs, crashes needing a hard reset (causing total memory erasure) will make it untenable to develop serious software because one loses everything. All software that a user has ever developed is lost.
Here's what has happened to me.
In final tweak/adjust/debug stage, XEQuting a 473-line program caused the screen and keyboad to freeze. None of the keystroke combination reset procedures in the manual worked.
i.e. neither of the following freed the lock-up.
C + GTO
C + R/S + i
Consequences were very bad. I had to stick a pin in the back. I therefore lost not only this long program but also ALL other code I had entered for previous programs.
Hoping that this was just an unfortunate rare occurrence, I re-typed the entire 473-line program from notes I had kept. When I tried to XEQute it again to resume where I had left off, it worked partially (just as before) and then, at exactly the same place in the data entry, exactly the same problem happened again.
I'm therefore faced with having to type it all in yet again (that is, AT LEAST one more time, and probably more than one). Naturally, I'll try stepping through it next time, but when it crashes again, I will again be back to zero.
This is very exasperating and time-wasting.
It is also extremely discouraging. I had planned to build up gradually (and post to an HP calculators users' forum site) a library of most-useful structural engineering code that would just lie in memory, preserved by always having a spare battery pair and replacing batteries carefully. This unrecoverable crash means I can expect to lose the lot. And that is a big big disincentive to software development on a calculator I can't trust, that has no possibility for external filesaves.
I have posted a request for help on the excellent calculator users forum at www.hpmuseum.org .
I have asked,
1) Has anyone else had any similar experience?
2) Does anyone have any ideas of what type of code might cause it, so that I can search through my code to try to find MY bug?
3) Has anyone any ideas about how to force a non-destructive reset when the instructions in the manual dont succeed?
Be in no doubt, if this problem persists and we can't find out why, then the HP35S, which is otherwise a superb calculator, becomes totally crippled for all serious users. One cannot write serious programs on a calculator with no save facility if it suffers from occasional crashes that wipe the entire library of all programming ever done on it.
I have sent a detailed description of this problem to the calculators section of http://wwemail.support.hp.com and my report has been acknowledged by an autogen email from HP Calculator E-mail Support <email@example.com> with reference number KMM20282596V46293L0KM.
I don't know if you will be interested to see the 473-line code that caused this, but I am attaching details in a PC Micro$oft Word file, just in case you would like to see it.
The program is for structural engineering design. It does a rigorous parabolic-rectangular stress-block analysis of a rectangular RC section for a required moment of resistance in accordance with BS8110:Pt1:1997. It then recommends a section size (for the user to over-ride with his/her own choice), and, finally, optimises the compression and tension reinforcement bar sizes for minimum steel weight in the user's chosen section size.
Probably-suitable date with which to test it are:
H=360 (over-ride suggested value)
B=300 (over-ride suggested value)
Bar diameter = 20
Please note that the above program is still only in its final testing/debugging stage. The problem is not that the program doesn't work. Its that it kills the calculator so totally that I hae had to wipe out all programs in it with a hardware reset.
I hope you can help.
Many people on the users' forum are starting to say the same.
Oxford and London