Calculators

can you not get a graphcalc app?

Good idea. There are plenty of graphing calculator emulators available:

Android graphing calculator apps:

I repair and collect HP calculators (for no obvious reason) and have a few graphing calculators (HP48G and HP48GX and TI-82 and TI-83) in my collection. However, I've never bothered to learn how how to use the graphing feature on these as the various graphing programs on my PC and Andoid tablets are much better.

Oh swell... I forgot to remove the batteries from the TI calcs and now they've leaked.

(...)

This one looks good. Free version: and paid version: I couldn't resist and paid for it. The free version was good enough but I just hate the ads. What got my attention was the algebra and 3D graphs:

Incidentally, for every day calculations, I use an HP41C emulator my my Samsung S6 phone, Google Nexus 7 tablet, and a few odd Android devices: I don't use the programming features but prefer an HP41C emulator because I use an HP41CV on my desk at home. It's nice having the same calculator everywhere.

No it isn't. Not for me, anyway. I like to have the real thing with real buttons on it and apply the same philosophy to my test equipment as well

- all of which does one thing only and that thing brilliantly, takes up a shed-load of space and weighs a ton (which is why about 1/3 of the house is unlivable in). No emulators around here!

What do you think of the TI-82/83/84 series? And how do TI calcs measure- up against their HP competitors in your estimation?

Been there; done that; who hasn't?

With some things I agree, but I'm not seeing any upside to a separate graphcalc.

NT

My missus would agree wholeheartedly with you on that.

No opinion on usability, features, or functions. I've never used or even know how to use a graphing calculator. I only collect and repair them. I can tell you that most HP calculators are better built, but more difficult to work on than TI and Casio. Many of the HP keyboards are unrepairable if you spill something sticking on them (very common problem). If you expect your new calculator to last as long as your Sharp EL6400 lasted, I suggest the older HP49/50 series or the new HP Prime, and take very good care of it. If price is a problem, try Casio.

There are quite a few comparisons and reviews found by Google:

I should have known better as this happens every time I put away a calculator full of batteries, and then forget about it for a few years. I had these wrapped in cellophane which helped contain the KOH, but it still rotted the contacts. I inspected most of the collection and found some more leaking batteries.

Careful what you ask for. If buttons are what you want, buy an Android tablet or smartphone and run an emulator. Any BlueGoof keyboard will so the buttons. Plenty of BT number pads available: While this probably the most expensive implementation of a graphing calculator, it's also probably the most powerful, versatile, portable, and cool looking.

I still use my various calculators out of habit, but mostly I've switched to using various emulations. I regularly use 3 Android and 2 ChromeOS devices, most of which will run these emulations. This year, I did my taxes using a calculator with paper tape emulation to make checking easier. Yesterday, I used an HP41c emulation on my Samsung S6 to grind out the changes needed to reposition a big dish antenna from AMC-8 to AMC-18 satellites.

Incidentally, there are also web apps, which work the same on most every device that supports internet access and runs a decent web browser. Try this: To start, click on the 3 bars in the upper left. Grids are under the tools (wrench) icon in the upper right. If you want to such web apps cheaply, I suggest a Chromebook. I bought a 15.6" Acer something factory referbished (essentially new) for $185 on eBay (and then someone stole it). Make sure you get something with 4GB RAM and an Intel processor.

Yeah, I do some of that. I have a smartphone, which I only use as a tablet computah. The actually talking on the phone is done with an ancient LG VX8300 phone. However, I'm finding myself using the smartphone more as a camera and my various other digital cameras are collecting dust. I'm also connecting various "sensors" to my smartphone and tablet which act more as viewers and recorders than instruments. An IR camera is next on my shopping list. None of these features do the job "brilliantly". They do it adequately and can be replaced with something better and often cheaper as these become available. You might want to calculate what the storage space for your single function devices is costing you and consider consolidating them into multifunction devices.

Duracells, right?

Never use Duracells.

-- john, KE5FX

Sharp did some very nice calculators - but I don't know if they still do.

Casio seem to have taken up the baton.

You can get Casio minimalist graphic calculators in supermarkets for pocket money prices - their range goes *MUCH* higher than that.

Last time I had that problem with Duracell was in a TV remote - they'd been in there years.

Its not like it never happens with the cheap brands.....................

What do you think of this model:

Someone said the batteries/battery on these are hard-wired in so tight you can't replace them without trashing the calc., but apart from that fatal flaw it's a great piece of kit. What say you, Jeff?

No brand is safe IME.

I make sure that alkaline batteries don't stay in appliances very long and make damned sure dead ones are promptly removed. If we've had a power outage where we've used the flashlights for any time, they all get new batteries. Batteries are too cheap and a ruined widget, too expensive, when it's needed most.

I couldn't possibly do that, Jeff. Collecting great big, f*ck off-sized

less. I simply couldn't bear being knobless.

Why on earth would I want to calculate how much all this wasted space is costing me? You think I like being reminded of it? I'm so stuck in the past I haven't even adopted calculators for everything yet. For instance, I sill use a slide rule for certain purposes like currency conversions where they're faster and more convenient. They also provide a more intuitive feel for relative currency movements than mere figures on a display do in the same way that old- style analogue meters beat digital for stuff like peaking tuned circuits. I may be stuck in the past, but I'm happy to be so. :P

I'm also stuck in the past. Most of us tend to stop growing at whatever age we feel most comfortable. I also have that problem, but do what I can to avoid it and try to blunder forward with progress.

I decided that I needed a karma recharge, to compensate for all the evil things I did last week. I was going to fix one of the TI calculators and send it to you for free along with a sympathy card. Well, it didn't quite work out. There was a reason I buried those calculators in the "test me some day" box.

I took them both apart to thoroughly clean out the corrosion, blow out any water, and fix any visible damage: That's my kitchen cutting board, the only unclutted flat work area left in the house. Of course, I "fat fingered" the disassembly resulting in buttons everywhere. I got the buttons properly arranged on my 2nd try. When re-assembled, the TI-82 worked but had a dead vertical column on the LCD screen. The TI-83 would not accept keyboard input and seemed to have a dead clock osc. Now I remember why I didn't like older TI calculators. They tend to have display connector problems. HP uses zebra connectors, which are much more reliable. So, you don't get a free graphing calculator, unless you want one of these losers.

Not this time, although in the distant past, I had sworn never to intentionally buy Duracell alkalines again because of all the damage they had caused.

These were Costco Kirkland batteries, which I thought were fairly immune to leaking based on a few years experience. They also had the highest capacity when I tested various brands with a West Mtn Radio CBA II battery discharge tester. Well, that was until this happened: You don't need to discharge them in order for them to leak. They leak quite nicely in the box. I took the picture on Oct 4, 2016.

The reason for leaks is that as batteries discharge - either through usage or gradual self-discharge - the chemistry of the cells changes and some hydrogen gas is generated. This out-gassing increases pressure in the battery. Eventually, the excess pressure either ruptures the insulating seals at the end of the battery, or the outer metal canister, or both.

So, it might be hydrogen outgassing from self-discharge that wrecked my AAA batteries. However, I think that's baloney. If you've ever worked with hydrogen gas, it is very difficult to contain. It will leak through most materials by diffusion, including through metals. A rubber seal won't do much to keep hydrogen inside the battery. Liquid KOH will blow open the seal, not hydrogen.

This also seems rather odd because I had purchased and used several other sizes of Kirkland batteries at the same time, that didn't leak. In other words, something in the design or construction of this particular batch of AAA batteries made them prone to leaking a year or two after they had officially expired. I've always wanted to design a "warranty timer" but it looks like Kirkland has beat me to it. I don't see why Kirkland would advertise a 7 year "shelf life" on the package unless they expected it to fail catastrophically after 7 years.