Copyright (C) 2001-2006 Mike Sebastian

Frequently Asked Questions:

Where can I find a manual for my calculator?
Are you a successor in interest to any defunct calculator manufacturer?
Do you, or someone you know, repair old calculators?
What is the best calculator for my child/student?
What calculators have been recalled?

Where can I find a manual for my calculator?

Below are resources which may be able to help in locating a replacement manual for a calculator.

Ataba has manuals for many of the calculators they manufacture available for download. Ataba manufactures calculators for other brands. Hence, their manuals might be useful for similar models sold under other brands.

Calculated Industries has manuals for many of their calculators available for download.

Casio has manuals for some of their currently marketed calculators available for download. Casio can also provide photocopies of manuals for older calculators by calling their Document Center in New Jersey at 973-252-7570.

Datexx has manuals for some of their currently marketed calculators available for download. Since their calculators are manufactured by a handful of different OEMs, including Ataba and Kinpo, their manuals might be useful for similar models sold under other brands.

Hewlett-Packard has manuals for their currently marketed calculators. Some are available for download. Others can be ordered in hardcopy form. David Hicks, through his Museum of HP Calculators, also sells scans of manuals on CDROM for many of the old models of HP calculators.

Sharp has manuals for some of their more recent products available for download. From this page, select the appropriate calculator category. Then select the blue "Manuals" link near the right side of the page to see a list of available downloadable documents. If you cannot find the appropriate manual, you can always contact support.

Sonin has manuals for their calculator products. Manual downloads are available from each individual product page.

Texas Instruments has manuals available for download for their currently marketed calculators and some discontinued calculators here. Manuals are not available for all discontinued calculators. Alternatively, you can always contact their support group.

Vintage Calculators. The following collector web sites have some manuals in PDF format available for download:

Are you a successor in interest to any defunct calculator manufacturer?


In case you are wondering, I was effectively asked this question by someone who should have known better.

The vast majority of the calculator manufacturers, or semiconductor manufacturers who made calculator chips, came into existence in the 70's, and rapidly disappeared. Some were aquired by other firms. Others went bankrupt. If you are a law firm seeking these answers, it is time for you to get on Lexis or Westlaw and start searching - after all, you will be billing you client for the search.

Do you, or someone you know, repair old calculators?

While myself and other collectors do repair calculators, we do not do it commercially. Obtaining replacement parts can be difficult. Most replacement parts come from other calculators. New parts are almost impossible to find. Further, we don't want to be liable for the loss or damage to somebody else's calculator.

Personally, I have found most of the problems with old calculators to be the result of leaking batteries. Sometimes, the solution is as simple as cleaning battery contacts. Other times, more extensive work and cleanup is required. I have occasionally found bad solder joints or cracked copper traces on circuit boards.

There are continuous and ongoing discussions about the repair of Hewlett-Packard calculators at The Museum of HP Calculators. This site also contains numerous well written articles on repair of HP calculators. Further, Dave Hicks, the curator of the Museum also sells a CDROM set which contains service manals for some HP calculators.

What is the best calculator for my child/student?

I can't answer that question for you. I don't know your child/student. I don't know their age or grade in school, their aptitude for math, nor their future educational plans. However, I can offer some guidance is selecting an appropriate calculator.

Different Calculator Logic Types

Not all calculators operate the same way. Some calculators don't even have an equal key! Today, calculators are sold using one of several available logic types. Most scientific calculators currently being marketed utilize an equation algebraic logic system, which is great for rote memorization, but terrible when it comes to actually learning or doing math. Reverse Polish Notation and traditional algebraic are much better in this regard.

A Few Comments On Quality

(The following comments about calculator quality are based on my own observations of many models of calculators. Besides observing the external quality and usability of various calculators, I have taken many calculators apart to see how well they are constructed internally. Again, these comments are based on my own experience, your mileage may vary.)

The best quality calculators in the sub-twenty-dollar price range are those made by Texas Instruments and Casio. Sharp brand calculators, while of reasonable quality, are not as well made as the Casio or Texas Instruments calculators. Hewlett-Packard markets two calculators of reasonable quality for under twenty dollars - the HP-9S and the HP-30S. Radio Shack markets several calculators of reasonable quality under their own name.

Texas Instruments and Casio calculators are well made both externally and internally, and they use higher quality materials than other brands of calculators. Externally, Sharp calculators and the HP-30S are as well made as the Texas Instruments and Casio calculators, but internally, they use cheaper materials, and the internal manufacturing quality is not as high.

If your are faced with purchasing a generic calculator, the Datexx and Aurora brands are of reasonable quality. The external appearance is good, and the internal construction is better than other brands of generic calculators.

At higher cost is the Hewlett-Packard HP-33S. The HP-33S has both RPN and formula algebraic modes. Its suggested retail price is $65, but can be found for as little as $50. Early indications are that the HP-33S is fairly well made. (Until recently HP sold the HP-20S (traditional algebraic, programmable, no fraction capability), and the HP-32SII (RPN, programmable, fraction capabilities). These calculators were discontinued in early 2003, but are still available as new-old-stock on eBay and from some vendors.)

Currently marketed graphing calculators all appear to be of reasonable quality. But, for a mininmum cost of fifty dollars, and an average cost of around one-hundred dollars, you should expect higher quality than that found in the cheaper calculators.

What calculators have been recalled?

I am not aware of any formal recalls of any calculators sold to consumers. However, because of algorithm bugs in the embedded ROMs, calculator manufacturers have been known to repair/replace a calculator with the bug.

Early HP-35 calculators, manufactured by Hewlett-Packard had a bug with the exponent (ex) function. HP offered to repair any calculators with the bug, and many owners did return their HP-35 for repair. Now, an HP-35 with the ROM bug is fairly collectable.

In 2000, Texas Instruments offered to replace new models of the TI-30X IIS, TI-30X IIB, TI-34 II, and TI-40 College II calculators after a ROM bug affecting functions which utilized logarithms was discovered. The replacement offer expired January 31, 2001. The text of the notice can be read here. (This notice was removed from TI's web pages shortly after the replacement offer expired.)

The above should not be interpreted to suggest that only HP and TI have had ROM bugs. Many other calculators, including modern calculators, have had ROM bugs, but the manufacturers have not chosen to offer replacements, or replacements have been provided under normal warranties.

Most graphing calculators sold by HP and TI now have flash memory to store the firmware that would have previously been stored in ROM. Errors are occasionally found in the firmware, but new firmware can be downloaded to the calculator by the user. Check the manufacturer's web site for information about firmware updates.


Last updated September 3, 2006