All my content and ptohos
Calculators
I don't collect calculators but I often have
opportunity to grab one or two with some electronic junk. From simple
abacus, through slide rules and mechanical stepper drum machines, to
electronic units, sometimes even programmable.
First wide-spread calculators were abacus calculators, a typical with
round pieces of wood on steel rods in wooden frame. Abaci are used even today,
especially in small shops in Ukraine or Lithuania, and calculating on
them can be really fast if it's done by experienced person.
In engineering, slide rules were popular calculators. Contrary
to abacus, slide rule allows to divide and multiply numbers, but it can
be used to compute logarithms, powers, roots and some trigonometric
functions. The set of logarithmic scales on sliding parts made the most
time-consuming computations easier. Slide rules were made of different
materials, in different sizes (from full-sized ones to pocket-size
units) and in different shapes (linear, circular, even with replaceable nomograms). There were also specialised rules to convert units or
compute values (in ballistics, airplane navigation, architecture,
cryptography etc).
Simultaneously more expensive mechanical machines were made. Mechanical
arithmometers could be used to perform all 4 operations using counters.
Arithmometers with pinwheel - gear with different count of
protrusions, were manufactured till mid-80s. Abaci and mechanical
arithmometers are used even today, especially in former Soviet Union
countries. Why? Because they don't need electricity.
Since late 70s electronic calculators became cheaper and more
accessible. They became smaller too, from large, tabletop units to
pocket, microprocessor-based battery-powered calculators known today.
Nixie tubes became replaced with VFD displays, VFD with LEDs, then LCD.
Some really old units had CRT display, but they were so expensive that
they never gained popularity. First calculators were transistor-based,
sometimes even had ferrite memory. Later units were made of TTL chips,
later were one-chip constructions with dedicated chips.
Click a unit to get information, photos and tips...
