|35s: Crash and weird behavior|
Message #1 Posted by Mike Mander on 25 Aug 2007, 9:22 p.m.
Since posting my photo gallery and noting the unreliable nature of R/S (and ON/C) when interrupting a loop, I have had a few interesting things happen.
I was programming the 35s and testing some routines and goto-ing between differing labels when suddenly the calculator froze with only the "RPN" and "PRGM" annunciators lit - I had just done an XEQ label to start running my test program. No amount of R/S, ON/C or ON/C-GTO keypresses would make it responsive again. I looked in the manual for further keystrokes but it was basically locked up. Nothing I could do would bring it back to life. After leaving it for 10 minutes and trying again in vain to reset it from the keyboard, a paperclip reset finally rebooted it, but also cleared memory. Not 100% sure if it was supposed to clear memory but it did.
After that incident, I was doing some looping speed tests to compare it to some other HP calculators and suddenly noted that the R/S and ON/C *did* work reliably now after the reboot/reset. No more flaky behavior - every push of the R/S key or ON/C would instantly interrupt the program, just as it had on all my previous HP's. Suddenly, totally different behavior from before! Very interesting...
Then, a little later, I was trying to mess around with vectors and for the life of me, could not get the 35s to accept vector input (the first time I had tried). If I typed, for example, [12,35] and pressed ENTER, the calc would come back with SYNTAX ERROR with the curser placed on the 3 after the comma. Didn't matter what display mode, angle mode anything... it would never accept any sort of vector I tried to input. If I recall (not 100% sure), it maybe would accept a single element vector, but for sure never 2 or 3 element vectors.
I then tried to enter a vector ([12,35] for example) as an equation. The editor happily accepted the vector but then gave the same syntax error when I pressed ENTER to evaluate the equation. I also tried [REGY,REGX] as an equation, to build a vector from the stack, but got the same SYNTAX ERROR.
In frustration, I then wrote a quick program which would generate a vector (just [12,35]) and, lo and behold, that worked and placed the desired vector in the X register! Without really looking further at the manual, I thought maybe vectors could only be used in programs (silly, I know) and wrote a trivial program to generate a vector from the X and Y registers - basically just the same [REGY,REGX] equation I had tried in the equation list before. This worked so I happily played with vectors for a few minutes and then tried keying one in directly again. This time it worked!!!
So from that point onward, the calculator has always accepted vector entry as it should, both directly keyed and in the equation list. Very strange. Almost as though something was corrupted in the calculators OS, both initially after installing the batteries for the first time and then again after a reset. Somehow running the vector equation program "fixed" the glitch and it has behaved as expected since then.
Since the calculator was so flaky right after installing the batteries (weird R/S and ON/C behavior) and then giving me the hard crash, it might be wise for any new user installing the batteries for the first time, to do a paper-clip reset immediately before something glitches and causes a loss of calculator memory. Obviously I can't really be sure if an initial reset would have helped in my case...
Just thought you all would be interested in hearing about this.