While browsing the computer displays at the Science and Technology Museum in Ottawa, I spotted something familiar. It was a Hewlett Packard calculator; the same model as the one on my desk. It seems that my favourite calculator is actually two years older than I am. After a bit of digging, I discovered that this calculator (which I bought for $5 at a garage sale) is not only historic, but is also a collector's item. They regularly sell on eBay for over $100.
The online HP Museum has a collection of simulators for various models. Since they did not have a simulator for the HP-35, I wrote one in JavaScript for them. The result is a very faithful simulation with the exception of some rounding errors. Both the HP-35 and the JavaScript produce rounding errors, but they do so in different situations.
