|Re: HP 15C keyboard|
Message #9 Posted by Les Wright on 1 Feb 2007, 2:00 a.m.,
in response to message #8 by Thor Lansen
I still use Free42 more than the real thing.
The main weakness of the 42S (and indeed the saintly 15C) is that it has all of that program memory and fingers are the only way to get programs into it.
Recently, I have been turning quite a few listings from this site's software library into barcode and RAW files using hp41uc. The barcode gets the programs into my 41CV and onto cards. The RAW files I can use directly, usually with no modification, in Free42 on my Palm. In that setting the programs are impressive to use. I am pretty interested in JM Baillard's numerous higher level math routines (error function, complete and incomplete gamma functions, beta functions, Fresnel integrals, etc.) Most of these routines (which are, incidently, examples of compact and efficient programming) take a few seconds on the real calculators to return results if iteration over, say, terms of a series or continued fraction are needed. Yet on the Free42 they return results almost instantaneously, or at worse will take a second or two if "tough" arguments are presented (e.g., computing the incomplete gamma function Gamma(a,x) by continued fraction when x is much less than a). More over, the displayed results are typically correct to all twelve digits, since the internal 25 digit accuracy gives more guard digits than you could possibly want.
I have even ported the PPC ROM Romberg integration routine IG for use on Free42 in preference to the built-in integrator. I think it is a little faster, and one can choose to display or "print" interim results--plus the code isn't a black box to me and I know what it is doing in its compact 90 steps.
The 42S was my first ebay calculator purpose. I spent $300 (plus taxes and shipping, which added another $70 I think) for what is basically a working but dented field quality calculator. It works, and it came with manual and box. Since then I have seen 42's in better shape for half the price, but I try to live without regret. I have spent a little too much for some things, but have been compensated by some great finds, like an excellent HP80 from our friend Namir for only $80. There is some karma here.