Nintendo tumbler puzzle Nintendo tumbler puzzle The Nintendo tumbler puzzle, also known as the "Ten Billion Barrel" in English and originally in Japanese, is a mathematical puzzle in the style of Rubik's Cube. It was invented by Gunpei Yokoi of Nintendo in 1980 and was covered by (until the patent expired in March 1995 due to non-payment of a maintenance fee). It consists of a "cylinder" of transparent plastic divided into six levels, together with a black plastic "frame". The frame consists of upper and lower discs that are joined together through the middle of the cylinder. The top and bottom levels of
Lucid 3-D Lucid 3-D Lucid 3-D was a spreadsheet package that began in the MS-DOS era; Windows support came later. Sam Redman and Michael Stanford incorporated as PCSG corporation (Portable Computer Support Group). Their Lucid 3-D spreadsheet was marketed by DAC. Lucid 3-D was considered noteworthy at the time for being "the only major memory-resident spreadsheet available for the PC." The selling point of the product was being "three dimensional. "Any cell" of the spreadsheet "can contain a complete other spreadsheet that you can access with a single key"stroke." Another technical feature was what their ads called "not only minimal recalc, but