Can't do that. My cell is a no frills phone-phone. No apps possible, whatsoever. Kids think it's a steampunk model.
Slowly I get the feel this old SR-50 is toast. Even the pins of the SCOM chip appear to have started some sort of dry-rot, all the way up to and possibly into the chip.
[...]-- Regards, Joerg http://www.analogconsultants.com/
I also have a drawing table, and electric pencil sharpener, and an electric eraser. And a good supply of D-size blue grid vellum. And a blueline machine.
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
We had those until we took the plunge and bought Android phones in January. We make very good use of them and haven't been sorry at all.
Working as designed. ;-) I hated SR-50s. I would have stuck with my slipstick if they were the only alternative.
They wear out after a certain amount of use. My SR-51 eventually expired but largely because it fell off my belt clip and got run over.
I am surprised one lasted as long as this.
We once tormented one by turning the clock speed right down so you could see the refresh. ISTR the TI patents are available (not sure if online) so you should be able to get full circuit diagrams for the implementation. Actually I think it was a 56 we did that too.
I suspect wear and tear - nearly 50 years operation isn't bad. Most of my calculators have died within a decade. Although I do still have a working SR-59 and print cradle in the loft somewhere as I could not bring myself to part with it.
I think it is the even longer periods of use inbetween that does for them.
That is 6 segments on so 12mA a segment average. A "1" might well be lower by a factor of 3 depending on how much juice the core takes.
Regards, Martin Brown
(also a fan of TI calculators)
Yeah, one of the reasons I decided to hand it over to E-waste now is that some of the domes appear to have a hole rubbed in, and not just through the plastic. This calculator got some extreme workouts because I did not have a computer for my early filter designs. My dad had an IBM-5100 but it ran APL which I never really warmed up to.
I could have swapped the CLEAR and EQUALS domes with ARCTAN or other lesser used ones. But there comes a limit. Walmart sells a nice HP scientific calculator for around $50 and it has RPN.
They were never very bright but nice small segments and very contrasty.
Me, not so much, I have to say that afetr I married I began to prefer HP. Feels like better quality and I started to really like RPN. My wife brought an HP-11C into our marriage and that's the one I use right now. We could never divorce because then I'd have to give up the 11C, and they don't make those anymore :-)
-- Regards, Joerg http://www.analogconsultants.com/
We are on $5/mo pay-as you-go plans. Plenty for us. Virgin does have smart phones but then AFAIK it pops up to $40/mo or so and I can't see us using that. I hate it when people fidget around with their handheld gizmos all the time. Some are literally obsessed. Middle of a nice dinner ... *BING* ... "Oh, that could be so-and-so sending a text" ... and out comes the schmart fone. Yuk.
It's been good to me. I could not possibly have calculated all those filters with a slide rule. Plus back then HP's were truly unaffordable for the masses, you had to be on a professor's pay grade for those.
-- Regards, Joerg http://www.analogconsultants.com/
The first calculator I ever encountered belonged to a school friend. It came back from the US as his dad was a drugs rep. HP20 I think.
I RPN Obscure Very Find - Yoda.
I was just lazy and liked entering formulae in normal order without having to think. I got away with mental arithmetic and writing SR for "slide rule" in the margin until first year uni. Answers to 3 sig fig and SR did not go down at all well with our crystallography supervisor so I got a calculator. SR51 - I have fond memories of it too.
Regards, Martin Brown
If you're that cheap, you can do even better.
Some people shoot people but that doesn't mean guns aren't useful. Some people bury the people they've shot, but that doesn't mean shovels aren't useful.
I was a poor married student in '73 when I took the HP plunge. It was about ten weeks pay for me (three weeks, combined, for the two of us). I wouldn't have bought an SR-50 at any price[*]. I think professors were paid a bit more than that, even then. But then again, I'm not so cheap that I can't afford more than a $5/mo. mobile phone now, either. ;-)
[*] Five people bought SR-50s the summer of my senior year and three bought HP-35s (amplifier design course).The HP owners all got As and the TI owners *all* flunked out. How's that for demonstrating the difference! ;-)BTW, I used a slipstick and got an A in the class - but it was smokin' by the end of the final. The HP guys walked out early. I resolved to join the HP generation right after that final. I got the HP45 in November, IIRC.
Sure, RPN is easy. Just enter all the nouns then figure out what you want them to do (verbs).
The EE and ME profs took to calculators immediately. The prevailing reasoning was that college was expensive already. A couple of hundred bucks didn't make a significant difference. Calculators did (the problems could be made much more realistic). Some the lesser departments tried to ban calculators but the dean of engineering overruled them (though academics, like Obama, don't bother with rules they don't like).
It's not about being cheap, I just don't need any more than that.
[...]
Well, now you know a SR-50 owner who did not flunk out 8-)
HP's were totally unaffordable over in Europe back then unless you had rich parents. I thought about a Sinclair ZX81 but then decided to invest that money into something real. Part for a monster RF amplifier.
-- Regards, Joerg http://www.analogconsultants.com/
I didn't until I had one, either. Same deal with a calculator, computer,...
17% success rate still isn't great, particularly against 100% for HP. ;-)$400 (1973 dollars), when my income was ten times that wasn't exactly "affordable" but I did it anyway. It was an investment.
Those sold for $20 in the US.
I remember $99. (very cheap at the time).
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
I paid $20 a few months before the bottom fell out of the market for that computer. Swallen's, a chain based out of Cincinnati put 1,000 on sale at that price. I still have one, somewhere. I didn't like the thing, and gave that one away. it was followed by a string of other cheap 8-bit computers, till I bought a Commodore 64.
My 1983 vintage HP 41CV died some years ago. Maybe I should search the web for repair ideas.
Ummm... there is sci.electronics.repair. If it's many years old, I suggest you remove the N batteries before they begin to leak.
Start at: There's a section on the HP41 series:
Fixing the HP41CV is not easy. Fixing the 82104A card reader is difficult: I have an HP41CX (with all the accessories, many programs, and all the docs). It's my daily "work" machine. There's very little inside that will actually fail. What happens is the electrical contacts between boards and assemblies needs cleaning or someone broke the plastic posts under the screws, which now doesn't supply enough compression to get a decent electrical connection. Be VERY careful when removing or inserting the bottom screws. The mating plastic posts are not very strong and are easily cracked.
Also, mine has a chronic case of lousy bettery contacts. I've temporarily fixed a few of these by just spinning the 4 N type batteries. I've also seen calculators where only one out of the 4 batteries is drained, while the others are at full charge. I have no clue what causes that effect since they're all in series.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Well, I only knew one guy who spent his complete (!) savings and then some on a programmable HP with printer, memory extension and whatnot. AFAIK he never achieved his master's degree. From the TI guys that I knew maybe half. Which was high for my alma mater, back then they had a
83% flunk-out rate. So 50% for TI guys, 0% for HP guys. I don't know about the guys with Commodores and others.I was a highschool student at that time but with a dire need to speed up my filter calculations and stuff. For me $400 was definitely unaffordable. The highest paying vacation job was a grueling one in a meat factory and that paid $3-$4/h. All muscles ached, some you didn't even know you had.
-- Regards, Joerg http://www.analogconsultants.com/
Only in an inventory sell-off. I had the prices from the US back then, in magazines. They were well over $100. Which was still a ton less than in the Netherlands though.
-- Regards, Joerg http://www.analogconsultants.com/
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I was paid $2/hr as a technician ($2.25 by the time I graduated) for a
20hr max week. My wife made the same as a nurse's aid in a nursing home.[...]
Couldn't get tech jobs where I was living. The meat factory job was really tough. Lifting batches of 36 to 42 big long and wet Italian salami sausages into smoker's racks all day long was my main job there. In essence the perfect weight lifter training. I did not want to become a weight lifter but it was the highest-paying job in the area. Mainly because nobody wanted to do it or they didn't last through the first day. The bicycle ride was 7-8 mile each way and in the evening that was painful. Made enough money during school break to buy myself a used shortwave transceiver and some other ham radio gear, things a school kid could normally never afford.
-- Regards, Joerg http://www.analogconsultants.com/
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