50g Warmstarted in the future!

[Carsen]

Hello,

I was performing linear equations on my HP 50g today when it all of a sudden turned off because I depleted my (non-rechargeable) batteries. So I installed my new batteries and turned it back on. I was curious to see if it would have affect the WSLOG command, so I executed the command to find out. The latest warmstart was reported at a date of 10/28/18 @ 14:58:59 which is in the future!!! (see the screen capture below). And yes, the date in the calculator is accurate. Look at the screen capture.

What makes this more interesting is that I have an alarm set on 10/28/18 @ 14:59:00. This is only 1 second off from the latest WSLOG record. I set this alarm on 10/21/18 @ 17:02:41 according to my 50g alarm log.

Thoughts on what is going on? Questions and comments welcome.

Edit: I forgot to add the pictures.

[DavidM]

(10-27-2018 02:31 AM)Carsen Wrote:  What makes this more interesting is that I have an alarm set on 10/28/18 @ 14:59:00. This is only 1 second off from the latest WSLOG record. I set this alarm on 10/21/18 @ 17:02:41 according to my 50g alarm log.

Hey Carsen -

I have no insight into what happened with your warmstart log, but I'm curious as to whether your alarm triggered as expected yesterday. It would seem like more than a coincidence that the WSLOG entry was directly adjacent to an alarm like that.

[Carsen]

Hello DavidM,

My alarm that I set for 10/28/18 @ 14:59:00 did not activate.

I agree that this is a rare coincidence too because the alarms should have no impact on the WSLOG command. As I keep testing the HP 50g's alarms and documenting them, I will keep a close eye on the WSLOG to confirm that this was just a weird phenomenon. My goal is to see if this is connected to the alarms that fail to ring.

[TravisE]

No idea if this could possibly have a connection of some sort, but I seem to recall experiencing some interesting quirks in system clock behavior upon battery removal. I thought I recall observing once that after brief removal of main power (AAA-cell or USB) and reconnection the clock (and return value of TICKS) continue running normally, but if power is removed for long enough (somewhere around a minute or so, I think) it seemed like the clock was somehow reverted to a state near the moment when AAA power was removed and then froze there until power was resupplied… or something along those lines. But I just tried that on my old HP 50g now and could not reproduce the behavior I thought I remembered. After several minutes without power, the clock was still okay.

But now here's the weird part. When I reinserted the battery, the calculator for some reason immediately did a warmstart, which was unexpected. Normally removing and reinserting a battery when the calculator is off does not trigger a warmstart. Then, I checked the WSLOG and got this entry:

C-11/07/18 18:15:59

It is currently 2018-11-04 18:32 as I write this, and I confirmed the clock was correct when I did the test (and it still is). So now *I* have a WSLOG entry in the future! But in my case, I have no alarms set, so apparently no relation there.

I wonder if there is a hardware clock that can get lost on power loss but then is somehow restored later during bootup (by some sort of “backup” clock, maybe?). Maybe the “future” WSLOG times are some sort of side effect of this happening? In particular, I wonder if the datestamp listed in the WSLOG in this case doesn't in fact correspond to the time at which the simulated Saturn CPU happened to next be scheduled to “wake up” and perform the next time-based task at the point when the power loss occurred.

[Carsen]

HI TravisE,

(11-05-2018 12:44 AM)TravisE Wrote:  I thought I recall observing once that after brief removal of main power (AAA-cell or USB) and reconnection the clock (and return value of TICKS) continue running normally, but if power is removed for long enough (somewhere around a minute or so, I think) it seemed like the clock was somehow reverted to a state near the moment when AAA power was removed and then froze there until power was resupplied… or something along those lines.

I tried it with my HP 50g and it did exactly as you described. I removed all 4 AAA batteries @ 19:56 and reinserted them at 20:01. Then I powered on the unit and viola, the clock displayed 19:51. However, my unit didn't warmstart (as it should) and my WSLOG was unaffected.

(11-05-2018 12:44 AM)TravisE Wrote:  In particular, I wonder if the datestamp listed in the WSLOG in this case doesn't in fact correspond to the time at which the simulated Saturn CPU happened to next be scheduled to “wake up” and perform the next time-based task at the point when the power loss occurred.

I believe this to be a solid hypothesis. In my case, the next scheduled "wake up" was my alarm (even though it didn't ring) & in your (TravisE's) case, the next scheduled "wake up" is your automatic power on performed by the HP 50g approx. every 3 days or so. I have no knowledge about the emulated saturn CPU part of the 50g so I cannot comment about it (except that I should learn about it!).

Either way, both our 50g units performed a warmstart, whether intentional or not, and reported a future WSLOG entry. There might be a consistent behavior to document here.