Using Free42
14:04
Slide Rule vs Calculator Showdown: Decilon & HP-35
12:29
Comparison of HP42s and DM42 features
16:29
HP 42S Scientific Calculator from 1988
27:10
Comparison of HP 10C, HP 11C and HP 15C Scientific Calculators
2:02:22
Mozart - Classical Music for Brain Power
25:05
Algebra - How To Solve Equations Quickly!
22:02
Hp 42s Calculator Repair & Upgrade - Keyboard repair & 32kb Memory Ram Upgrade
23:31