Four types of RPN

[hansklav]

(09-02-2014 10:40 PM)Den Belillo (Martinez Ca.) Wrote:  

(09-02-2014 10:17 PM)Joe Horn Wrote:  Wasn't there a 3-level RPN in some ancient desktop models?

several. the hp9100 for instance
in pocket calcs; there were also a few in the Novus/nat semi lines, and their Argentine clones.

(09-03-2014 04:57 AM)Paul Dale Wrote:  

(09-02-2014 10:17 PM)Joe Horn Wrote:  Wasn't there a 3-level RPN in some ancient desktop models?

The Sinclair Scientific would be a 2-level RPN device.

For these early 2- and 3-level RPN calculators I propose the term ‘pre-α type’ (pre-alpha type).

Hans