42S Registers wacky in fast mode

[brh]

Hello all!

I've lurked here on and off for a bit, having used HPs my whole life and maintaining a small but serviceable fleet of calcs. The 41C was one of my earliest introductions to programming, and has always had a special place in my heart, save for its awkward batteries and bulk. So, my go-tos have long been Voyagers and Pioneers. I don't know why I never picked up a 42S until recently; but now I have one, and I love it!

Strange little question, however. It's a ROM A, and I decided to mess around with the so-called 'fast mode.' I have noticed, after doing the instructions for fast mode under program control, my (numbered) registers act all crazy. Regardless of whether I'm in fast mode or not.

If I do 1000; ENTER; STO 01; RCL 01, I get x: -6.62577767124E153
If I do 1000; ENTER; STO 02; RCL 02, I get x: "nAüdAef≤÷"
If I enter something and attempt a SIGMA+, I get an 'Invalid Type' error.

Haven't figured out how to get things back in check aside from a full reset... Anyone have any clues?

Cheers - Brian

[Paul Dale]

This looks like some kind of corruption problem triggered by fast mode.
The solution is to not use fast mode

- Pauli

[rprosperi]

(04-15-2016 03:37 PM)brh Wrote:  Haven't figured out how to get things back in check aside from a full reset... Anyone have any clues?

Press [EXIT] and [Square Root] together => This does a Machine Reset; Note this is not destructive - it may lose some flags/minor settings, however is does not lose any memory or programs.

See HPX Exchange V1N6 which is full of 42S Info. This is included on the DVD sold by Jake Schwartz here. A must-have for any true fan.

Also, see here for Jean-Francois' interesting 42S article, elsewhere on this website.

[brh]

(04-15-2016 09:09 PM)Paul Dale Wrote:  This looks like some kind of corruption problem triggered by fast mode.
The solution is to not use fast mode

Hah, thanks! I came to that conclusion on my own pretty well
I realize I didn't really say as much, but I was more curious if folks had seen this behavior before, or if it was indicative of anything other than "just don't do that."

(04-15-2016 09:54 PM)rprosperi Wrote:  Press [EXIT] and [Square Root] together => This does a Machine Reset; Note this is not destructive - it may lose some flags/minor settings, however is does not lose any memory or programs.

Thanks — I figured there was a way, but for some reason just wasn't having much luck with Google today.

Thanks for the links as well. Time to crawl a little deeper into the rabbit hole.

As an aside, I brought the 42S in to work today to see if I could figure anything out (I couldn't, so I just did a terminal-short to reset and then wrote a little (graphical) Monte Carlo pi simulation on my lunch break)… that meant I had 4 HP calcs on my desk… and I'm just a web developer!

—Brian

[lyuka]

Display RAM would corrupt at low voltage (e.g. less than 2.8V) of the batteries at double speed.
How about replacing the batteries to new set of SR44?

SEE ALSO "Crystal resonator replacement for double speed 42S"