Not Circuit Related

3:16 Bible Texts and Donald Knuth's book

Cannonball Puzzle from my father-in-law

Fidelitone and FonoTwin , Dad's dual turntables

Heathkit , how I got started

Machine Epsilon ,  after "Hello World"

Mechanical Design Guide

Sag and Tension  Background , and approximation for Cosh (x)

Sag and Tension Graphing Calculator for suspended wire antennas or cables

"The Enciphered Letter" ,  Russian to English translation

USPS Intelligent Mail barcode (IMb)