Sites for Collectors and those Interested in old calculating devices, including electronic calculators, slide rules, weird and wonderful old computing machines.
Mechanical computing on an industrial scale. The world's first large scale real time multi user systems. One of these systems was built and tested in 1920 capable of supporting 1000 terminals and a sell rate of 250,000 per minute.
All things geek, techy and retro. Talking about technology from the past, also my collection of 70's calculators.
I am also a Photoshop user, some artwork is on display.
This site is about collecting and using HP calculators.
Back in the 70's and the 80's, HP was leading the market. The RPN calculation system proved to be most efficient and made HP calcs preferred choice of engineers, teachers and students.
This site also describes how to use financial Hp calculators to solve european compound calculations.
A website for the East German Söemtron ETR range of electronic calculators. Covering the rebuilding of a very badly kept Söemtron 220, this site has circuits, logic diagrams, photos and more information for these increasingly rare early Eastern Bloc electronic calculators.
The HP-35 was HP's first pocket calculator. The earliest and the only production version 1 "Red Dot" had a red dot to the right of the power switch that showed when it was turned on. This page contains references to probably most of known and still existing Red Dots. The list will be continuously updated when new information will be gathered.
Museillo sobre la evolución de las herramientas de cálculo. Desde el ábaco, pasando por regras de cálculo, calculadoras electrónicas y programables y ordenadores.
