In 1983, a special eight-digit calculator with memory hit the scene. No bigger than a credit card, at 54 mm x 85 mm, it was astonishingly slim, at just 0.8 mm, and light, at 12 g. The SL-800 represented the culmination of the advances in digital technologies that were considered to have ushered in an era of slim, lightweight, compact products. Having provided the foundation for the development of state-of-the-art high-density mounting technology by Casio, the SL-800 attained, in 2013, an Essential Historical Materials for Science and Technology (or Future Technology Heritage) designation from the National Museum of Nature and Science in Tokyo, as a calculator realised in an extraordinarily slim, compact form.