John Wolff is a retired electrical engineer from Melbourne, Australia. His background is in electronic instrumentation, control systems, and computers. He has worked in private industry, public utilities, and academia for over 35 years, most recently as an IT manager in a government research laboratory. For a second full-time job he is a sole parent to two teenage kids. For hobbies, he tinkers with pianolas and mechanical music, and reverse-engineers antique calculators. For occasional light relief he sometimes builds robots with the kids at an "alternative" school.