From: utzoo!decvax!harpo!ihnp4!stolaf!minn-ua!jlw
Newsgroups: net.misc
Title: Re: HP Calculator Stack Depth - (nf)
Article-I.D.: minn-ua.265
Posted: Thu Jan  6 20:57:10 1983
Received: Fri Jan  7 06:14:08 1983

~v
Hmmm.  Looks like I'm on my own.

The fundamental reason for not having more than 4 registers in the stack
is that it wouldn't save you any keystrokes.
I paraphrase from something I picked up at the bookstore here where I bought
my HP-15C and HP-16C: PPC Journal, Special Issue B, 1979.
Given the problem
                   1.2
                1.4
             1.6
          1.8
         2
using a four-level stack the solution is
1.4 E^ 1.2 y^x 1.6 x<>y y^x 1.8 x<>y y^x 2 x<>y y^x
which is a 13 step solution, counting quatities as signle steps.
A five-level stack gives
2 E^ 1.8 E^ 1.6 E^ 1.4 E^ 1.2 y^x y^x y^x y^x
which is also 13 entries.  Hence, no advantage.
If you need a larger stack for intermediate results, use the addressable
storage regsiters; that's what they are there for.
I think I'd have trouble keeping track of where everything in a large
stack was, and end up starting over more than once.

The observant among you may wonder what a 1979 PPC Journal was doing
in a bookstore selling 1982 calculators.  I wonder as well.
Those of you who are too observant noticed that 'single' was misspelled.
A thousand pardons for that transgression of netiquette.

					Jeff Woolsey
					University Computer Center
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