HP 65/25 shout-out in interview with Paul Lutus


Paul Lutus designed electronics for the NASA Space Shuttle ...



I read many years ago that Paul Lutus wrote his own OS for the Apple []. He seems to be one sharp dude.

It was nice to hear about Lutus again. For many years I wondered what happened to him.



In 1977 I was looking through my local library for anything about microcomputers and came across an article in Popular Electronics by Lutus describing his game program Space Flight for the HP 25. In the game you control the thrust of a spacecraft orbiting two planets and try to land on one. A 2-D, 3-body lunar lander game!

I wanted to play it on my shiney new SR-56 so I taught myself RPN and converted it. What fun! I still have my listing and a photocopy of his. To compare: the 25 version uses 49 steps and 7 registers; the 56 version uses 92 steps and 10 registers.

Last year I emailed Paul and reminded him of that article. He said he wrote several popular articles back then. I encouraged him to post to this forum but I haven't seen anything.


To compare: the 25 version uses 49 steps and 7 registers; the 56 version uses 92 steps and 10 registers.

In 1977, I was writing programs for both a HP-67 and a TI-59 for real operational use on the nuclear submarine on which I was stationed. I found that the RPN version would typically require only about 60 percent of the memory assets of the AOS version. Your example independently confirms that estimate.

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