[newRPL] interested in RPN mode?

[Claudio L.]

(10-21-2019 08:12 PM)toml_12953 Wrote:  Wouldn't that slow it down considerably? I'd like to see an eight level stack machine that works just like a 4-level machine other than the number of levels. Back in the '70s, just before introducing the Altair 8800, MITS had a 7-level stack desktop calculator that you could add an external octal programmer to. I was about to buy one when the Altair came out and my plans changed. With 8 levels, you should be able program almost any practical engineering equation without using intermediate storage registers.

Well, not considerably but yes, RPN mode would execute with a slight penalty compared to RPL because of the stack trimming. Now in RPN you always have to copy the T register when you drop arguments, or move up all elements when you insert, so compared to other RPN machine no, it wouldn't be any slower.
RPL would also suffer a tiny penalty because the main loop would have to check for the RPN flag to decide which mode is in, but probably too small to measure.