Not on this site, but deserves a mention: Joerg Woerner's detailed history of the development of the TI-88.

Not sure why it was broken (other than my on-going efforts to remove old code that is not PHP7 compatible, and also a recent fix of a security vulnerability) but the for sale page works again. (I thank an alert and patient buyer who, instead of moving on, took the trouble to notify me.) Enjoy browsing, and please do let me know if you are looking for something specific, as I have many calculators not visible here, as I have not yet ascertained their condition, made pictures, or set a price.

I thank Khan Janny (@Reboot_Ex) who spotted a cross-site-scripting vulnerability on and posted it to the Open Bug Bounty Web site. The vulnerability is now fixed (I hope).

There was a Texas Instruments calculator in the database about which I knew nothing. Nothing short of an old post, that is (, which appeared to have described a data entry device that might double as a calculator. Today, I learned that the post was, in fact, an April Fool's joke, posted a month early (or not, if one believes the PS.) So the TI-64 entry is now officially removed from the database.

Two new models (well, models that were not previously in this database) were added today: the Casio fx-181P and the MBO Alpha 610 PR. Thanks to Ambrus Zsban from Hungary who brought these to my attention.

No, the 500 is not the number of errors, but the error code that many users saw when trying to look at lists of calculators by manufacturer, or at individual calculator pages. It appears that as a result of some changes to the innards of Joomla! or one of its components after the latest update, the scripts that generated these listings and individual pages were called more than once, resulting in fatal errors when functions were about to be redefined. Thankfully, Google is kind to us Webmasters: This morning, I received a warning e-mail from Google that many of the pages on this site were inaccessible, and thus, the problem was present only for a few days.

This is a unique addition to the museum that, albeit non-programmable, deserves a special place: the Casio CFX-200 is one of only two types of scientific calculator watches ever made.

The Items for sale page is working again.

I have not noticed that I broke this page when I switched servers a few months back. Guess I'd not make a good capitalist!

That said, if by any chance you try to purchase something and notice a glitch, please do not hesitate to let me know, especially if you have reason to believe that PAYPAL already got your money. (Although if PAYPAL takes your money, I get notified by e-mail anyway, so I'd know if the server misbehaved and complete the transaction manually.)

In the past two days, I made many small changes trying to improve the behavior of the Facebook plugin on auto-generated pages. As a result, old comments pretty much disappeared (oh, they exist somewhere in Facebook's bit bucket, but they don't show up on the calculator pages anymore.) I apologize for the inconvenience.

Today, was upgraded to use the latest version of the Joomla content management system. If anything is broken, please do not hesitate to let me know.

A set of newsletters (several issues of Programmable Calculator News and It's About T.I.M.E.) have been added to the Texas Instruments section of the Library. I received these newsletters from Palmer Hanson just a few days before he passed away. Thank you very, very much, Palmer.

Several new items have been added to the Texas Instruments section of the Library, courtesy of Palmer Hanson.

I came across to rare Casio programmables on eBay last month: the FC-200 is a financial calculator, whereas the FM-300 is an altogether unique, non-scientific formula programmable.

It has been a while since I last bought a brand new calculator, but the HP-39gs was available on at a deep discount.

A few days ago, I enabled Joomla's built-in cache mechanism to speed up this Web site.

Unfortunately, Joomla's cache feature is a tad too aggressive; it was also caching the calculator detail page. Since the content of this page is dynamically generated, caching it is not such a good idea. Basically, it meant that once you looked at a calculator page, the page remained "stuck" on that calculator, refusing to show details of any other machine until the cache expired.

This problem is now fixed, and I was able to keep the cache feature running, thanks to an excellent Joomla plugin, CacheControl.

Updated the page on the Facit C1-13 with a brief repair story and a detailed example of Töpler's square root algorithm.

I received a great deal of information about many Sharp programmable calculators previously unknown to me from Dmitry Sobolev. The database is now updated to reflect Dmitry's additions and corrections.

The museum now also has a Google+ page.

The museum now has its own Facebook page.

For now on an experimental basis, I added a social network plugin so that pages can be Liked or commented on Facebook, and +1'd on Google+.

Added an article on Michael Berger's Robotron K1000μC emulator kit.

Thanks to a donated unit that was in much better shape than my damaged Nixdorf LK-3000, I was able to update the LK-3000 page.

It is now possible to click on calculator images shown in popups on the Other Calculators page, and get a linkable page with the image and its title. This should help those who wish to link to specific non-programmable calculators shown on this site.

I keep making minor improvements to the CMS site. I finally fixed the code so that the manufacturer name and model number are now shown in the page title (and will correctly show up in search services, I hope.) I also fixed our local search facility: calculator detail sheets are now properly shown when a calculator appears as a search result.

I successfully transferred most of the content of to a content management system, Joomla. Using a CMS will make it easier to keep this site up-to-date. As part of this effort, I also eliminated some outdated HTML code: for instance, I no longer use small images for Greek characters or mathematical symbols. More complex mathematical expressions are now rendered using the MathJax library.

Of course, there are probably some gremlins. Some links may not be updated and still point to old content that is no longer available. Hopefully though, most of the content will appear as intended.