John Wolff's Web Museum

Adwel W504 Full-keyboard Adding Machine

AdwelW504.jpg (6kb) Adwel Model W504, S/N 799113
Functions: Add, subtract, sub-total, total; manual operation
Digits: 7 keyboard, 8 printer
Dimensions: 8-1/2"W x 14-1/2"D x 6-1/2"H
Weight: 15 pounds approx
Manufactured: Bergen, Norway, 1960s.

Nameplate.jpg (4kb) MakersTransfer.jpg (6kb)

The "Adwel" Model W504 is an attractive full-keyboard printing calculator or "add-list" machine. Although this particular model is one of the most basic office calculators, it still manages to contain well over one thousand manufactured parts, and its mechanism is far from straightforward.

These notes contain a series of pages describing the essential features of its construction, followed by a detailed description of its principles of operation and some of its peculiarities.


  1. Layout and construction
  2. The add and carry mechanism
  3. The keyboard and keylinks
  4. The register control mechanism
  5. The printing mechanism
  6. Leading-zero supression
  7. Description of operation

Original text and images Copyright (C) John Wolff 2003.
Use at own risk; beware of errors; suggestions for improvement welcome.
Last Updated: 12 February 2003

Back to:   Home    Calculating Machines    Printing Calculators