HP-42S with flush and recessed display

[walter b]

Hi all,

Are there any differences between those two variants of that calculator besides the obvious geometrical ones? Does contrast or readability differ between both models? Or is it just the same LCD with and without a protective cover? Thanks in advance for enlightenment.

d:-?

[Bill (Smithville NJ)]

(01-25-2014 08:09 AM)walter b Wrote:  Does contrast or readability differ between both models?

I've always found the recessed display without the protective cover had a noticeable higher contract. It was enough of a difference that I sold the ones that had the protective cover and only kept the recessed display ones.

Bill

[Mark Hardman]

(01-25-2014 08:09 AM)walter b Wrote:  Are there any differences between those two variants of that calculator besides the obvious geometrical ones?

My three 42Ss with the flush bezel have ROM version "A". My lone 42S with the recessed display is ROM version "C".

Mark Hardman

[John R]

Yes, the recessed-display models are easier to read, regardless of viewing angle or lighting conditions. I think that both models actually use the same LCD, but that the presence of the extra protective layer in the flush-display model reduces the contrast. I've never had the heart (or the cash) to crack into two HP-42S calculators to verify, though.

A flush-display and a recessed-display HP-42S will also likely have different ROM versions. This difference is not inherently related to the display or to a common underlying factor, but simply reflects the fact that units with later manufacture (i.e., those with the recessed display) may have newer ROMs.

[Bill (Smithville NJ)]

Quote:A flush-display and a recessed-display HP-42S will also likely have different ROM versions.

On the Units I have had, all the Protected Screen units had ROM Version A while my recessed screen units have Rom Version C. I've never seen a ROM version B.

The one nice thing about ROM A is that you can enter "Fast Mode" which will speed up the calculator somewhat. I cannot do that with my recessed screen Rom C units.

Bill

[Forrest Switzer]

I also have three. All are of the older flush display models, which do have more "reflected shine" off the display. I did also have two later models with the recessed, and non glare screens, but I just like the earlier model better. I sold the newer ones for as much as $400. I just like the older display better.