Memmory retention without battery in pioneers - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- Thread: Memmory retention without battery in pioneers (/thread-1835.html) Pages: 1 2 Memmory retention without battery in pioneers - ElectroDuende - 07-16-2014 03:07 PM This morning I discovered th HP27S that I usually have in my desk turned upside down and with the battery compartment open (and empty!). a colleague explained me that he urgently needed LR44 batteries for his laser pointer to make a presentation yesterday afternoon, and that was the only place to find them. So I got the batteries back, put them on the calculator and powered ON, expecting to have lost all the formulae (quite a lot, useful for daily work), and was greeted by a "MACHINE RESET" message. Anyway, all the formulae were still there after about 15 hours without battery! I suppose that the clue is that nobody pressed ON while it was unpowered... RE: Memmory retention without battery in pioneers - Massimo Gnerucci - 07-16-2014 06:30 PM I'd have something to say to this coworker... RE: Memmory retention without battery in pioneers - walter b - 07-16-2014 08:17 PM (07-16-2014 06:30 PM)Massimo Gnerucci Wrote:  I'd have something to say to this coworker... I guess what - and I'd back it. RE: Memmory retention without battery in pioneers - Csaba Tizedes - 03-28-2016 02:00 PM I don't know why the engineers are forget this knowledge during the years. My HP35s shows the BATTERY annunciator on the last week and after a short period (few key presses) the calc is turned OFF. I think that this is not a big problem, my 15C without batteries keeps the memory for hours and I do not removed the batts from the 35s. On Sunday I can't to change the batteries, today morning I checked, the calc is not turned ON (I began to worry), but I know that, just 3-4 days before seen the BATTERY sign first time and I don't used the calc during weekend. Fresh batts installed properly and - of course - all of my EQS and PRGS are lost. WHY? I want to ask that engineers whose short bio and pictures I can see in the HP Journals from the 70's and 80's which kind of calculators uses?!? My math teacher said: If these (new) engineers will design a bridge, I'll buy a boat. I must to say: these new "calculators" are worthless. How it is possible to afford such a company (HP) such this is happen?! Just simple change the words: "equations" to "family pictures", and you can feel it deeply. Csaba RE: Memmory retention without battery in pioneers - Massimo Gnerucci - 03-28-2016 02:21 PM They don't make capacitors the way they used to anymore... :) RE: Memmory retention without battery in pioneers - rprosperi - 03-29-2016 12:55 AM (03-28-2016 02:00 PM)Csaba Tizedes Wrote:  I don't know why the engineers are forget this knowledge during the years. I don't think it's the engineers that have forgotten, but rather the market insists on cheap, cheap, cheap. One way to meet the price the market demands is to use cheaper materials, less refined engineering designs, etc. A new 35S ($60) costs less than 1/4 what a new Voyager cost, if you adjust the dollars to same-year values. (rough guestimate) Would you pay$250 for a 35S, even if it were much higher quality? Would millions of other customers? We are all victims of the never ending demands for cheap, Cheap, CHEAP! RE: Memmory retention without battery in pioneers - Steve Simpkin - 03-29-2016 02:30 AM It is even worse. An HP-15C costing $135 in 1982 would be equivalent to$339 in 2016. http://www.saving.org/inflation/inflation.php?amount=135&year=1982 My HP-48SX was even higher at $656 in today's dollars. For pocket calculators though, I don't think anything beats the HP-65 at the equivalent of$4,070 today. And then at the opposite end of the spectrum there is the functionality I have in my Amazon Kindle Fire tablet that set me back $39 new (on sale, normally$49). RE: Memmory retention without battery in pioneers - Dave Britten - 03-29-2016 11:13 AM (03-29-2016 12:55 AM)rprosperi Wrote:  Would you pay $250 for a 35S, even if it were much higher quality? Would millions of other customers? If we were talking software quality, I might. After all, I paid about that much for a DM-41L and DM-16L, and will probably do the same for a pair of whatever the DM-42L ends up being. But we're outliers, of course. RE: Memmory retention without battery in pioneers - Marcio - 03-29-2016 12:11 PM I'd pay$250-ish for a 35s that had all the functionality of the 15C. I never understood why they decided to add memory and remove functionality over the years. Doesn't make any sense to me. RE: Memmory retention without battery in pioneers - Maximilian Hohmann - 03-29-2016 12:27 PM (03-29-2016 12:11 PM)Marcio Wrote:  I never understood why they decided to add memory and remove functionality over the years. Doesn't make any sense to me. I never understood why they keep adding memory without any means of backing that up somewhere. A micro USB or SD card connector costs only a few cents. RE: Memmory retention without battery in pioneers - Marcio - 03-29-2016 12:57 PM (03-29-2016 12:27 PM)Maximilian Hohmann Wrote:  I never understood why they keep adding memory without any means of backing that up somewhere. A micro USB or SD card connector costs only a few cents. The 33s/35s were designed for surveyors and similar who will take tests where graphing calculators or any other machine with ability to send and receive data are not permitted. That is why there is no USB, blue-tooth or anything like that. Still, they could have added (put back?) matrix capabilities and several other important features. RE: Memmory retention without battery in pioneers - Dave Britten - 03-29-2016 12:57 PM (03-29-2016 12:11 PM)Marcio Wrote:  I'd pay \$250-ish for a 35s that had all the functionality of the 15C. I never understood why they decided to add memory and remove functionality over the years. Doesn't make any sense to me. RAM chips are cheap. Good software developers aren't (see: 35S bug list). RE: Memmory retention without battery in pioneers - emece67 - 03-29-2016 02:49 PM The OFF current consumption of a 35S is around 8 $$\mu$$A, don't expect a capacitor can hold enough charge to sustain it for 17 hours. At least a capacitor that fits inside the machine! RE: Memmory retention without battery in pioneers - wojtek - 03-29-2016 03:07 PM (03-29-2016 02:49 PM)emece67 Wrote:  The OFF current consumption of a 35S is around 8 μA, don't expect a capacitor can hold enough charge to sustain it for 17 hours. At least a capacitor that fits inside the machine! My 41c (born 1981) keeps data and settings for 10 days after the batteries are taken off. The technology of the RAM memory applied in 41c was different and certainly more expensive than nowadays? RE: Memmory retention without battery in pioneers - emece67 - 03-29-2016 04:42 PM (03-29-2016 03:07 PM)wojtek Wrote:  My 41c (born 1981) keeps data and settings for 10 days after the batteries are taken off. The technology of the RAM memory applied in 41c was different and certainly more expensive than nowadays? Definitely, there's more than simply a matter of currents. A 41 has a greater power consumption when slept than a 35S. I do not know the details of the technology used on hp chips from that era, but I always assumed it was different than that used nowadays. In fact, the processor in the (full nut) 41 series is defined by hp as: "[...]highly intelligent, bit serial, low power, pseudo non-volatile CMOS processor". In any case, my point is that, nowadays, a capacitor will not cure our machines from loosing all data when cells are removed for a long period. RE: Memmory retention without battery in pioneers - rprosperi - 03-29-2016 07:50 PM (03-29-2016 11:13 AM)Dave Britten Wrote:  If we were talking software quality, I might. After all, I paid about that much for a DM-41L and DM-16L, and will probably do the same for a pair of whatever the DM-42L ends up being. But we're outliers, of course. Sadly true. There used to be millions of us (preferring high quality and willing to pay for it) however today, we are in the micro-minority. And HP (and most other mfrs) design and produce for the millions. Fortunately for us, SwissMicros still caters to us dinosaurs, at very reasonable prices. A bit OT: IMHO, the 35S s/w suffered more from poor testing than poor design/coding. The bugs are just about all corner cases, with several taking > 5 years to surface. RE: Memmory retention without battery in pioneers - Hlib - 03-29-2016 08:09 PM (03-29-2016 03:07 PM)wojtek Wrote:  My 41c (born 1981) keeps data and settings for 10 days after the batteries are taken off. The technology of the RAM memory applied in 41c was different and certainly more expensive than nowadays? My friend once a long ago talked the same about his HP - 41, but I disbelieved him. So, it was really nearly so. RE: Memmory retention without battery in pioneers - Massimo Gnerucci - 03-29-2016 08:33 PM (03-29-2016 08:09 PM)Hlib Wrote:   (03-29-2016 03:07 PM)wojtek Wrote:  My 41c (born 1981) keeps data and settings for 10 days after the batteries are taken off. The technology of the RAM memory applied in 41c was different and certainly more expensive than nowadays? My friend once a long ago talked the same about his HP - 41, but I disbelieved him. So, it was really nearly so. Have faith! ;) RE: Memmory retention without battery in pioneers - Dave Britten - 03-29-2016 09:21 PM (03-29-2016 07:50 PM)rprosperi Wrote:  A bit OT: IMHO, the 35S s/w suffered more from poor testing than poor design/coding. The bugs are just about all corner cases, with several taking > 5 years to surface. The infinite loop lockup was pretty bad. Any programmer can tell you that coding the occasional infinite loop is not a corner case. RE: Memmory retention without battery in pioneers - wojtek - 03-29-2016 09:42 PM (03-29-2016 09:21 PM)Dave Britten Wrote:   (03-29-2016 07:50 PM)rprosperi Wrote:  A bit OT: IMHO, the 35S s/w suffered more from poor testing than poor design/coding. The bugs are just about all corner cases, with several taking > 5 years to surface. The infinite loop lockup was pretty bad. Any programmer can tell you that coding the occasional infinite loop is not a corner case. Omitting labels and implementing jumps to line numbers is also designers mistake. It is a 30 years' old solution, very good for machines with 100 bytes of memory but implementing it nowadays in a machine with 30KB of memory was not an achievement.