These pages exhibit some non-HP calculators that were introduced anywhere from centuries ago to the late 1960's.

• Slide Rules
  • History
  • Basic Instructions and Straight Rules
  • Large Rules, Complicated Rules & Sectors
  • Circular Slide Rules
  • Cylindrical Rules
  • More (Mostly Straight) Slide Rules
• Planimeters
• Calculating Machines
  • Adding Machines
    • Dial, Slide And Chain Adders
    • Printing Models
    • Direct Adders (Comptometer, Burroughs & Speedee)
  • Four Function Mechanical Calculators
    • Large Hand Driven Models
    • Motor Driven Models
    • Curta Handhelds
  • The Amazing Friden SRW (With Automatic Square Roots)
  • How Calculating Machines Worked
    • Rocking Segment Mechanism
    • Stepped Drum Mechanism (Leibniz/Thomas)
    • Stepped Drum Mechanism (Curta)
    • Pinwheel Mechanism (Odhner/Baldwin/Brunsviga)
    • Monroe Mechanism
• Early Electronic Models
  • The Friden EC 132 (A very early pre-RPN calculator)
  • A Typical Late '60s Electronic Model (Sharp)

Go back to the main exhibit hall
Go to the first HP