-+x/ or /x-+ ?

[Trevor Palmer]

On all HP calcs up to the 20 series the basic oporators '-', '+', 'x' and '/' were in that order on the keyboard (reading from top to bottom). From the 10 series onward they appeared in the order; '/', 'x', '-' and '+'.

Was there a reason for the switch?

Did it cause comment at the time?

Am I asking a stupid pointless question? (OK no need to answer that one, I'm just curious, thats all).

Trevor.

[Frank Knight]

Just a thought as I set here an look at the 15.11$ Walmart ti-36x I use at work since nobody would bother to steal it, the newer order you mention are the same as the order on this new series TI. Could it be another case of, ;+} naaaa...must be an ISO standard we have not seen!

[Kevin Schoedel]

Even the earliest *desktop* calcuators used the "/x-+" pattern (HP9100), even when the corresponding handheld had "-+x/"; compare for example the HP45 vs HP46 or HP67 vs HP97. The reason for the "/x-+" order, presumably, is that the operations appear in "order of complexity" from bottom to top, with the precedent of adding-machine style keyboards with the big "+" at the bottom. I don't know the reason for the "-+x/" layout; my best guess is that it again lays out the operations in this "order of complexity", but this time from the inside out. That is, the "most important" operator, "+", is on the "home row" of the keyboard, that is, in line with the middle of the numbers, with "-" and "x" on the adjacent rows, and "/" left over at the bottom.

[Bert K]

How 'bout the fact calculators have:

789 456 123

and telephones:

123 456 789

Bert

[Viktor Toth]

That difference between calculator and telephone keypads, believe it or not, may be intentional. I believe I read it years ago in comp.dcom.telecom that when the first pushbutton phones were introduced, the keyboard was intentionally reversed by Bell, to prevent people who were used to calculator keyboards from dialing too quickly. I have no idea if it's true or not, but it sounds like a good story :-)

Viktor

[Bo Kristoffersen]

Although not related to HP keyboards, the inverted telephone keypad is one of my great dislikes. Before the world went global European telephones had calculator keypads (what else?), however, now we have adapted the crap US style, Bell or not.

With regard to the HP keyboards, I assume they just adapted to the world outside, first the keyboard, then the RPN.

Regards, Bo, Copenhagen

[Thibaut.be]

I live in Belgium (in Europe, as far as I can remember), and have *always* noticed, since the time I can read (30 years ago), that the order of numbers of the calculators and telephone was inverted

[steve]

How about the accountants that yelled because their pinky had to travel too far for the + key, thus putting it on the bottom.