Contextual keys?

[Orome]

At the bottom of my 35s there's a distinctly colored "a b/c" below the decimal key. Is this just identifying that key as the contextual full fraction entry key (in the same way as register names on other keys identify them as contextual keys?

Put another way, I guess, are those colors supposed to match?

[rprosperi]

The "a b/c" is in pink (on my machine) which is the same color used for all the Alpha labels and also the (I) and (J) registers, which is unfortunate as that could easily infer these are all somehow related, which isn't the case. A different color was used to clearly indicate these are modal primary keys and no shift is needed; I'm not sure if that is what you mean by contextual keys, but I'd guess so.

A better choice, IMHO, would have been to use another color for these last 3 labels, however the keyboard and surrounding bezel are already quite busy with various colors, so they probably opted to use one of the colors already in use. I think it would have been better to simply label them in white, which would avoid confusion as you've suggested, and certainly would not have confused any user into thinking these were primary key functions. Most likely it was a production/process cost issue that drove using the same pink color already in use.

[Orome]

Is "modal primary keys" the official term? I was wondering what to call them.

(03-16-2020 10:35 PM)rprosperi Wrote:  The "a b/c" is in pink (on my machine) which is the same color used for all the Alpha labels and also the (I) and (J) registers...

The "a b/c" color is slightly different on mine from the rest, which is probably just an accident of manufacturing.

(03-16-2020 10:35 PM)rprosperi Wrote:  ...which is unfortunate as that could easily infer these are all somehow related, which isn't the case.

I don't see that as an issue. They're all similar in that they "just work that way in context" (so they are semantically related, if not functionally).

[Joe Horn]

Just FYI, the 35s manual says (page 1-26), "The a b/c symbol under the [.] key is a reminder that the [.] key is used twice for fraction entry." This was copied verbatim from the 33s manual (page 1-22), since the 33s also has "a b/c" below the [.] key in the same color as A-Z (black). That in turn was copied verbatim from the 32SII manual (page 1-18), whose "a b/c" is also the same color as A-Z (either white or very light blue... I can't tell). So the concept of [a b/c] and A-Z being "modal primary keys" or "contextual keys" goes back to 1991, when the 32SII first appeared.

[rprosperi]

(03-16-2020 10:45 PM)Orome Wrote:  Is "modal primary keys" the official term? I was wondering what to call them.

Nah, that's just what came out while typing. By that I mean they act as primary keys (i.e. no shift keys needed) but only when in specific modes or conditions. In truth the [.] key can be used for fraction entry as part of normal numeric data entry and not a special mode, but when it sees the 2nd [.] entered (between the numerator and denominator) it basically realizes this is fraction entry.

I think you had it right as well, I just used different terms to explain it, to be sure we were in sync.

[Orome]

Joe Horn Wrote:  So the concept of [a b/c] and A-Z being "modal primary keys" or "contextual keys" goes back to 1991, when the 32SII first appeared.

Indeed! It's much clearer there that they are intended to have the same semantics (I should have looked at the 32SII first).

Interestingly, on the 32SII [ON] is identified (correctly) as "contextual" as well. So arguably the semantics were in place (or anticipated) farther back.