WP 34S -- Mode Data store with STOM

[burkhard]

On the WP 34S, using the STOM command it is possible to save all the "mode data" to one of the normal numbered storage registers.

The mode data are basically system flags that control angle mode, date formats, contrast settings and a bunch of other things. Per the v3.3 manual, there are 64 bits in the mode data.

I would expect that if I set the word size (WSIZE) to 64, I should be able to STOM 00 to store all the mode data to register 00 and then look at it (in base 2 mode) via RCL 00.
Because of the display width limitation, you won't of course be able to see all 64 bits at once, but can page through it (using arrow keys) 8 bits at a time. Thus, I'd expect to see 64 bits spread over 8 pages, 8 bits per page.

It almost does what I would expect, but not quite. When I do the RCL 00, I see bits 0→52, but not the whole 64 bits. So I have 6 pages of 8 bits plus an additional 5 bits on the highest page (53 bits in total, not 64).

So what's going on? Why don't I see all 64 bits? It works the same way on the hardware (v3.3T b3901) and on the iOS emulator.

Is there some limitation in the width of the storage register such that it can only hold 53 bits? If so, that would seem to defeat the point of STOM, because you'd only be able to restore the mode settings for the lowest 53 bits via RCLM.

Thanks for any clarification,
burkhard