So sad. Saffo has an interesting examination of the TR3, a calculator with a vestigial sliderule on the back. This strange creature was created as a "bridge" technology for sliderule manufacturers to work their way into the calculator market that was fast destroying their bottom line.
In hindsight, the effort was wasted. This is a perfect example of the tectonic shifts that take place in electronics—tapes to CDs, VHS to DVD—and dash the hopes and dreams of countless innovators and investors every year.