I collect slide rules and other historical computing artifacts. Most of these have interesting stories to tell…
Vizzini’s Calculating Table
A minimalist calculator from Italy
A cheater’s slide rule
A relic of past dishonesty
Mario Loffredo’s elastic calculating scale
A lost precursor of the Gerber Variable Scale
Shrinking Megabytes
Evolution of the Hard Disk
The Sliding Gunter
A fascinating transitional device
Stephenson’s little adder
Agents wanted!
Alpina or Curta?
Battle of the handheld calculators
Courvoisier’s spiral slide rule
A neat solution to the turn problem
A new mathematical robot
ENIAC, in real time!
Sabatini’s magnificent calculator
Even Mussolini was impressed!
Blue Velvet
The lovely Adix calculator
Beautiful Digits
Numeric displays of yesterday
A lovely gauging rule
An Everard style 18th century slide rule
A calculator hidden in a book
A truly intriguing device!
Kaufmann’s Posographe
A mind-blowing mechanism for exposure calculation
“Iron Felix” meets the Odhner calculator
Two pinwheel calculators compared
Elisha Kally’s water flow calculator
Made by one smart water engineer!
Slide rules for a new century
Tavernier-Gravet’s evolving slide rule technology
Piercing the unknown
IBM pluggable units
Meet E. W. Fritchley
A human connection across time and space
Sbernadori’s aerophotographical slide rule
Serving the Royal Italian air force
The Watkins exposure meter
Light metering, 19th century style
The ingenious Ifach adder
A carry mechanism with no gears!
The weird Logarex Typ-01
A most unusual circular slide rule
The Silver Jubilee Sinclair Sovereign
The Rolls Royce of pocket calculators
Troncet’s OTHER calculator
The Totalisateur dial adder
Numeri Mundum Regunt
Sexton’s Omnimetre
The calculation of MADness
Nuclear blast slide rules from the cold war era
Chairman Mao’s guidance
A politically conscious slide rule from China
Build your own airplane!
The Hoffman Airplane Calculator
The Professor’s calculator
The R. H. Smith helical slide rule
The Jeffers Calculator
Keeping farm animals healthy through a nutritious diet!
The Pose-Marre pen slide rule
An elegant device of mysterious origins
Bloch’s Gewicht-schnellrechner
A mechanical nomogram for weight calculations
The Ross Precision Computer
Accurate to five decimal places!
Torsion wire delay line memory
A forgotten storage technology
The Genaille-Lucas financial rods
An ingenious way of calculating with sticks
Martin’s huge multiplication table
A tool from the time of Napoleon
Lalanne’s glass slide rule
An unusual but sensible choice
Jacob Zedak’s wooden slide rule
Very nicely made!
The Data Scaler Proportional Rule
A Gerber Variable Scale clone
The Controller slide rule family
All four of them!
Pretty as a picture!
The Arnault-Paineau calculator
Badalamenti’s factorization slide rule
Well, not exactly a slide rule…
Meet a Mathematical Inventor!
Jean-Antoine Lafay’s Hélice a Calcul
Lieutenant Brenske’s Marsch-Zirkel
Navigation in the days before Waze…
A slide rule with a Wow!
An ingenious and unusual form factor
Wynne-Roberts’ hydraulic calculator
A nifty little calculating device
Three “pencil” slide rules
The perfect gift for the calculating geek!
Five Intel chips that changed the world
When Intel enabled the personal computing era
The small Small Calculator
A full-fledged slide rule 5 cm in diameter
How the Slide Rule got its Cursor
Three centuries of innovation
The gentleman and the carpenter
Two Coggeshall variants compared
Leib Stern’s slide rule
An unusual slide rule from an unusual source
Krüger’s calculating pencil case
A computer for every child, 1909 style
Gunter’s rule
One step before the slide rule
Webb’s Adder
One curiously shaped calculator!
Biorhythmic calculators
Where computing meets Pseudoscience
The Dimensator
Michaelis’s reinforced concrete calculator
The Ken+Add, inside and out
Small adder, big quality
Hand wired Memory!
What passionate hobbyists did back in the day
Farmar’s profit calculator
It slides, it rolls… and it calculates!
Locke’s “pocket” adder
Well, at least it’s pretty!
Black Gem
The Golden Gem adding Machine
The Xeroxed calculator
Ugly it was, but extremely useful!
Just a couple of relays
Shades of the ASCC!
The bare bones Hemmi 22
As simple as it gets!
Joe Gerber’s pajamas
A truly ingenious device!
Thacher’s monster slide rule
Over nine meters of logarithmic scale!
Chesterman’s Cattle Gauge
Don’t buy a cow without it!
Psychrometric slide rule
A relative humidity calculator
Stephens’ “Supremathic”
A completely different circular slide rule
El Calculador!
A Spanish multiplication aid
Glass and Paper?!?
The ALKU glass slide rule
Homemade hydrological slide rule
Handcrafted with amazing workmanship
Enter the Altair!
And the rest is history…
A bill full of holes
An electricity bill from the mainframe era
A Victorian “Calculator”
A must-have for the enterprising farmer!
Software by the yard
Punched paper tape storage
Chenevier’s memento
An unusual pocket reference from the 19th century
Fowler’s Universal Calculator
A circular slide rule from Manchester
A computer with a dial
Building a computer in 1967
The first PDA
The Apple Newton MessagePad
Mahogany and Celluloid
The K&E model 4053-3
Hard Fonts
Before inkjet, before laser…
Ivory sector
Earlier than the slide rule…
Odhner Pinwheel Calculator
Carrying fine childhood memories…
The Correntator slide adder
A simple adder with a neat trick
Not a Toy!…
The Kes-Add pocket adder
An Aluminum CPU
A classic air navigation computer
Magnetic core memory
Ahhh, the memories…
A stroke of serendipity
Gravet Lenoir Soho slide rule
A curious Hybrid
A rare transitional device
The enigmatic Spirule
Best way for finding a root locus!
The incredible Curta
A triumph of miniaturization