John Wolff's Web Museum - Slide Adding Machines

Mechanical calculator - Wikipedia

Mechanical calculator - Wikipedia

Marchant Figurematic

mark making – Art Bite Blog

Marchant silent speed model D calculator. one part has a date of

2009 Pittcon Final Program - Pittcon Web Archives

Prof. Dr. Torsten Wolfgang Kuhlen - Virtual Reality and Immersive

Vietnam Print, Vietnam Poster, Ha Long Bay, Saigon Art, Vietnam

John Wolff's Web Museum - Olympia

Crowned Plague – The Brooklyn Rail

Magic Brain Calculator, c. 1950-1969 - Machine, Calculating

Progress is fine, but it's gone on for too long.: The Magic Brain Calculator

Magic Brain Instructions

TCoCD: Magic Brain Pocket Calculator

Magic Brain Calculator (Japan) w/instructions Unused