solar powered programmable

[hugh steers]

why isn’t there a solar powered programmable. i want one. as far as i know, hp never made any solar calculators. presumably this was because (a) their models always had excellent battery life and (b) all case series had at least one programmable and that didn’t mix at the time.

however, in these heady days of graphical user interfaces with animated dogs and paperclips, you’d think that someone could make a programmable solar calculator with some form of flash or nv ram.

ok, the casio fx-50f was programmable, but not in the sense i want with proper loops and conditional branches.

what am i supposed to do if im stranded on a desert island like robinson crusoe for years with nothing to do except develop highly advanced and even more sophisticated algorithms for contingent claims analysis, for instance.

[Chris Woodhouse]

Why on earth would you want one? When you can have one that takes inexpensive, readily available batteries that last for YEARS, what's the point? What happens to those programmes when you solar cells are hidden in your desk for a week while you are on vacation? Do you leave the lights on in your office when you are away so your solar calculator keeps it's memory? Not to mention every solar powered calculator I have ever used requires much more light to work than I require to use a calculator and that can be very annoying. If you want to help the environment, do something that will actually make a difference, like solar heat your house, convert your car to run a natural gas, or get a battery powered calculator so you don't have to keep the lighting in your office so bright ;)

Chris W

[hugh steers]

its not about the environment or anything like that. its about batteries being a
pain. they run down at inconvenient times. battery level indicators tend to be lame.
they say, low battery, then the next thing you know, its dead.
im assuming that when its in the draw for months, theres no power needed at all.
the memory is flash or something like that and the programs dont fade and the batteries
dont leak. thats better than having batteries that are dead when you come back from
vacation.
i think early solar models did have fairly poor solar performance. some later models
were a *lot* better. remember the ones that were good enough that only a small black
square at the top was needed for the panel. imagine those high gain panels but a bit
bigger (ie not so cheap) and there's your operation under low lighting.

also, the cpu could be variable power drain. if you want your program to run faster and its
sunny, just step outside and clock up your calculator. a real excuse for catching some
rays outside on a hot day. and you dont see people dissing kinetic or automatic watches. people know that batteries
are a liability.

i still want one.

[Peter Khor]

Casio's FX-3650P is a current model, has conditional jumps (basic Casio programming logic - what else would you expect ;) )- AND has a solar cell.

NOT available in the US market though.

[Peter Khor]

ops, forgot to add linky:

http://www.casio.co.jp/edu_e/product/other/programming/oth_program.html

[Mike (Stgt)]

There was (or is?) a solar model from HP, but not programmable: the HP-6S Solar -- with a backup battery.

OTOH, with a programmable solar model if the sun is down you have to hope for a bright full moon, otherwise your programms perish in the dark like a fly-by-night.

Ciao.....Mike

[Dia C. Tran]

The batteries on the LED models were a pain and still are if you use any of them. Since HP-41 battery is not an issue any more. My several 41's,10C, 20S, 32SII, 28 and 48's batteries last long enough for me to ever become an issue. I don't think solar make sense at all. I heard that the new 48GII and 49G+ have short battery life. Isn't it true?

[Tom (UK)]

Possibly because:

1) Most programmables are also graphic calcs and front panel real estate is taken up with display and buttons. Not much room for a solar cell left even on a non graphic programmable because of loads of buttons (OK HP42S did have room because of clever key use).

2) Programmable calcs are power hungry so either a large solar cell is required or internal battery or big capacitor to supply brief ammounts of high current. For long running programs capacitor may not be enough.

3) Programmable calcs require a reliable power source to keep the large ammount of memory alive. No big deal if you loose 1 memory space on a basic calc, but loosing loads of data on a programmable is a pain.