Sharp EL-506 Handheld Electronic Calculator

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This handheld electronic calculator is the first model in a series of scientific calculators sold by Sharp under variations of the designation EL-506 (e.g. EL-506A, EL-506H, EL-506P, EL-506W, EL-506WBK). This particular calculator has a metal and plastic case and thirty-nine rectangular plastic keys. The four lower rows of keys are similar to those found on many calculators, with ten digit keys, a change sign key, a decimal point key, four arithmetic function keys, three memory keys and a total key. The memory keys also can serve as keys for various statistical functions, as can two keys above them. The remaining keys represent a wide array of trigonometric, logarithmic, exponential and other functions, as well as a function key and an on/clear key. Above the keys is an on/off switch. A mark next to it reads: SHARP (/) Scientific calculator (/) EL-506. Behind this is a ten-digit LCD display.
The plastic back of the case has text that reads in part: ELECTRONIC CALCULATOR (/) EL-506. It also reads: NO. 06188695 (/) SHARP CORPORATION (/) MADE IN JAPAN BM.
The calculator has a brown plastic wallet.
[Advertisement], Los Angeles Times, March 1, 1980, p. SD_A3. Sharp EL-506 advertised as selling for $24.95. Image is of this calculator.
[Advertisement], Los Angeles Times, May 17, 1985, p. D20. Sharp EL-506 advertised as selling for $24.95. Image is of this calculator.
[Advertisement], Chicago Tribune, December 3, 1989, p. AA38. Sharp EL-506 advertised as selling for $18.88. This is not the same as the calculator in the collections.
Currently not on view
date made
Sharp Corporation
place made
Physical Description
plastic (keys; wallet material)
glass (display material)
metal (case material)
overall: 3/8 in x 2 3/4 in x 4 3/4 in; .9525 cm x 6.985 cm x 12.065 cm
ID Number
catalog number
accession number
Credit Line
Gift of John B. Priser
See more items in
Medicine and Science: Computers
Handheld Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History


The most reliable calculator I've ever owned, I still use it every day.
Just pulled this from the lab bench top to use in my office. Was given it probably around 1979-1980 for college and have used it extensively. Dad bought 2, one for me and himself, he worked for IBM. Have changed the battery once and probably need to again after sitting in a chemistry lab for a few years and having grad students and post-docs use it.
Mine is the same as all these in terms of durability but mine also spent some minutes in a bucket of water stood on by my infant daughter in 1990. A day in the sun and it's replacement went in the desk drawer. Still being used but just bought a EL-531TH and don't really know why.
I got mine in high school and have used it extensively in the years since. The stat functions were especially helpful during my studies, and for a while, I used it for at least an hour or two every day in the lab. It sat idle for a while, but I've brought it back out recently. As with many others' calculators, mine still has the original battery! How is that possible? Amazing calculator! I love it so much! I'm so gratified to see it's in the National Museum of American History!
I received one from my cousin in the early 90s when I was admitted to university. She use it before in the 80s. It was a heavy duty machine, I used it until the numbers on the keys started to fade. Even after being so heavely beaten it continued to work well. It never needed batery replaced. It had everything it was required to complete the lab calculations. Actually it served me so well, that nostalgy catched me this year, and I decided to find a good model on ebay and buy it back, just to preserve the memory of the past and recover back the good things which I had in my youth. Great machine.
I still have this calculator from 1980/81 and it still works perfectly. I used it all thru my undergrad engineering and grad school classes with no problems. It has taken a beating and come thru with flying colors. I wish all products were made so well.
Just changed the batteries in my 1984 EL-506P, googled for a manual to see how to open it, and found this page indicating that I'm using a piece of history. But I don't feel old or anything. Great calculator, I've never had a more ergonomic one.
There is a surprizing degree of difference twixt the 506 illustrated, and my 506A. The "A" has 6 columns of function keys, instead of just 5. Binary-Decimal-Hex-Octal conversions, boolean operations, and 6 memory locations were added, among other enhancements. I replaced the two LR44 cells 10 years ago (2008), but now the device has finally failed entirely. I have lots of other calculators, but nothing with as much functionality in such a small package, so I'm looking for a replacement.
Mine not only still works it is still in daily use. I also still have the instruction booklet which is what originally was in the pocket visible on the inside of the case opposite the device. It actually ran on the original batteries for 25 years!
Bought it in 1981 for the HEX function. Use it in the past to program the C64. Live in the Netherlands and still use it. Never change the batteries.. Hennie
I had either this model or a very similar Sharp in high school in the '80s. At one point a friend ran over my backpack, and the calculator, with their car tire. The faceplate bent a little, but it continued to work flawlessly for years. The thing was practically bulletproof!
i've got one and it still works, nice calculator actually, elegant design...
This is the calculator that got me through electrical engineering school in the mid '80's. I actually found it lying on the sidewalk while walking home from classes in my sophomore year. I loved it. It was a definite improvement over my clunky TI-30.
Likewise gents. Mine was bought for exams I was going through for a job in the oil business (offshore Aberdeen,Scotland) back in 1980 and it still has the original battery and cover. It's has been used briefly daily all these years. It has also travelled well. It's started off in Scotland and has been to Norway, France, Germany, Italy, Philippines, Yemen, Turkey, Gambia, Senegal, Libya and now resides in Malta.
I bought this calculator in 1980 for the Illinois professional engineering exam. Programmable calculators were not allowed. In December 1980, I installed a new battery the night before the exam to make sure it would not run out of power during the exam. It is still running just fine on that same battery. The automatic power-off function must work really well. I still have the instruction manual that came with the calculator.
I still use mine (EL-506P) everyday at work and it has the same battery. I wish I could find a new plastic case for it. The one I have now is falling apart......
Bought mine in 1980 during college and just came across it. Wasn't working so replaced the batteries but still didn't power on. Pushed the power switch a bit and showed some life. I took it apart, cleaned the contact for the power switch, put it back together. Works like new. (Be careful if you try this as the buttons and some small springs tend to fly out!) Even tried the old batteries and they worked! "Don't make 'em like they use to!"
Mine is still working as well.
Bought this calculator for high school math around 1980. This one also still functions with the original battery.
I still use this calculator a little daily and bought it in 1979. I have nerer replaced the original battery and it works fine.
"I swear i have used this since i got it in the 80's and i haven't changed the battery too, how strange."

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