<story><title>What Is RPN? Why Did/Does HP Use RPN? Learning RPN (1999)</title><url>https://www.hpmuseum.org/rpn.htm</url></story><parent_chain><item><author>disabled</author><text>It took awhile to learn RPN in undergrad in electrical engineering. But, once you learn it, it is so much easier to solve problems and it is much more efficient. You never go back, and you are less likely to make errors entering in equations compared to your peers. This is important on timed exams.&lt;p&gt;I prefer to always use RPN. MacOS has an RPN mode on their calculator, which one can activate by pressing command + R. On my iPhone I have an app called i41CX+, which is an HP-41CX emulator. I highly recommend the app, as the developer is constantly updating it. It probably is the most updated app I have of all of my apps.&lt;p&gt;Also apparently there are some companies that recreate old HP RPN scientific calculators: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.swissmicros.com&amp;#x2F;products&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.swissmicros.com&amp;#x2F;products&lt;/a&gt;</text></item></parent_chain><comment><author>pwg</author><text>My &amp;#x27;desktop&amp;#x27; calculator on my Linux machines:&lt;p&gt;&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;lashwhip.com&amp;#x2F;grpn.html&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;lashwhip.com&amp;#x2F;grpn.html&lt;/a&gt;&lt;p&gt;(yes, I know that xcalc has an HP mode, but I only learned of that mode long after I&amp;#x27;d begun using GPRN.&lt;p&gt;The calculator on my Android phone (I &amp;#x27;disabled&amp;#x27; the maker installed one):&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;play.google.com&amp;#x2F;store&amp;#x2F;apps&amp;#x2F;details?id=org.efalk.rpncalc&amp;amp;hl=en_US&amp;amp;gl=US&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;play.google.com&amp;#x2F;store&amp;#x2F;apps&amp;#x2F;details?id=org.efalk.rpnc...&lt;/a&gt;&lt;p&gt;And I&amp;#x27;ve still got my original 80&amp;#x27;s HP-15C.</text></comment>
<story><title>What Is RPN? Why Did/Does HP Use RPN? Learning RPN (1999)</title><url>https://www.hpmuseum.org/rpn.htm</url></story><parent_chain><item><author>disabled</author><text>It took awhile to learn RPN in undergrad in electrical engineering. But, once you learn it, it is so much easier to solve problems and it is much more efficient. You never go back, and you are less likely to make errors entering in equations compared to your peers. This is important on timed exams.&lt;p&gt;I prefer to always use RPN. MacOS has an RPN mode on their calculator, which one can activate by pressing command + R. On my iPhone I have an app called i41CX+, which is an HP-41CX emulator. I highly recommend the app, as the developer is constantly updating it. It probably is the most updated app I have of all of my apps.&lt;p&gt;Also apparently there are some companies that recreate old HP RPN scientific calculators: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.swissmicros.com&amp;#x2F;products&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.swissmicros.com&amp;#x2F;products&lt;/a&gt;</text></item></parent_chain><comment><author>senkora</author><text>Emacs calc-mode is RPN by default as well.</text></comment>