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