Calculating Things (2)

Casio fx-102

One of the very first electronic 'scientific' calculators introduced in 1979 as a cheaper alternative to the rather expensive electronic HP machines. The caculator is powered by an adapter or four AA batteries. The green LED-display consumes quite a lot of energy: 0.4 W.
Functions: Memory Calculations, Trigonometric/Inverse, Common and Natural Logarithmic functions, Exponentiations, Square roots, Reciprocals, Sexagesimal/Decimal conversion, statistical calculations, including two kinds of Standard Deviation.

Napier's rods

Also called Napier's bones because the calculation rods or sticks were originally made of ivory. An ingenious calculating 'machine' developed by the inventor of the logarithms, the Scottish mathematician John Napier.
For more info and examples surf to Educalnet.
This replica in a wooden box and accompanied by a booklet on Rabdology was mistaken for a toy and given to me for that reason.

Casio Digital Diary

Type: SF-4000. One of the very first personal organizers from around 1990. Dimensions: 12x7x1,5 cm. Build-in applications: Simple calculator, Telephone list, Memo, Scheduler, Calendar and Notes. Qwerty keyboard and a numerical keyboard. Small, vulnerable b/w display.

No possibility to connect the organizer directly to a computer or a local netwerk.

Psion Series 3

The first 'palmtop' or hand-held computer introduced by the British manufacturer Sinclair PLC in 1991. The little machine had an elegant mechanical design, a (too) small b/w display en a (too) small Qwerty keyboard.

16 bit CPU, 128 Kb RAM and Multitasking OS. Programmable with the programming language and compiler OPL. On the back side there is a slot for extra memory up to 256 Kb.

Built-in apps: System, Database, Editor, Diary, World Time, Scientific Calculator and OPL.

Psion Series 5

Introduced in 1997 by Sinclair PLC is the bigger and slightly heavier Series 5 hand-held computer. Again a sophisticatted mechanical design (sliding-clamshell design, whereby the keyboard slides forward as the device opens to counterbalance the display), a rather comfortable b/w touch screen display and a Qwerty keyboard that allowed normal typing.

At its heart was a 32-bit RISC-based ARM710T processor. EPOC 32 operating system. Memory 4 Mb upgradable to 16 Mb.

Psion Revo

The last organizer made by the British manufacturer Psion in 1999. Offspring of the Series 5. A very elegant, versatile and complete pocket computer with a wide black and white touch -screen. Built in two calculators: a simple desk and a sophisticated scientific calculator. The displays can be 'flipped': with the result displays either to the left or to the right of the screen. Cable communication with PC's.

Atari Portfolio

On of the first 'palmtop' or handheld computers. It ran under an OS which was file-compatible with the first IBM PCs. To the left a 128-K memory card which could be slid into the machine. To the right an extra parallel interface.
The light-weight computer was suitable for word processing and spread sheets and could function several hours on its internal battery.

Smart Watches

HP was the first in 1976 to introduce a calculator watch with LED display. It could also do calculations and calculations with dates. The watch was rather expensive. Later on a multitude of more of less cheap calcuwatches hit the consumer markets. Sony developed the first combination of a multifunctional calculating digital watch a LCD display. This watch was sold for 50 USD in Tokyo.

Plastic, cheap and impressive

To the left the plastic CalcuWatch ™ which cost five Euro ($ 4.50). It comes with one year warranty and a free battery. The time functions are limited but the calculator part has, apart from the basic functions: percentage, square root, Mem Plus, Mem Recall and Mem Clear. The keys are small and made of smooth rubber but can be used with ease while the watch is on the wrist.

Wooden Belgian Calculator :-)

Wooden calculator with five holes for five fingers. The thumb may serve as fast
memory in combination with the red wire.
This 'calculator' is a gimmick and is part of the Dutch hate/love - relationship with the Belgians. The 'theme' of the Belgian jokes holds that the Dutch are greedy.

Calculating Pencil Sharpener

To the right: the calculating pencil sharpener in a tiny 'desktop computer'. Lots of functionality: Date, Time, Alarm, Stopwatch, Snooze, Add, Subtract, Multiply, Divide and Sharpen.
To the left the calculating ruler. The keys are positioned alongside the ruler. Powered by a battery and a solar cell above the LCD.

Calculating Things (3)