My idea of the best calculator on the desktop is an HP 9100A/B or 9810, 9820, or 9830, Wang 720C, IME-86S, or a Tektronix 31. No native octal, but they can be programmed to do octal math. It's on-topic, these things are over 30 years old. Rick Bensene The Old Calculator Web Museum http://oldcalculatormuseum.com