|HP 41: a documentation odyssey |
Message #1 Posted by Miguel Toro on 12 Nov 2011, 11:04 a.m.
I have zero knowledge on the legendary HP 41 series of calculators and derivatives (C, CV, CX, CL … even Z?). From times to times I have been tempted to acquire one, but prices have always been too high to really justify the disbursement, thus I never really felt any urgency to read the extensive documentation available.
Guided by my “everything 34s” infatuation, I followed with interest but at the same time with increased distress this post about a polynomial solver for the 34s. Apart from the, IMHO, unfair treatment towards Valentín Albillo, there is what I consider the real jewel : Ángel Martin’s post of Albillo’s solver for the HP 41. Could I, even with my infinite ignorance on the subject, port this to the 34s as a programming exercise? Naively as always, I said yes and began trying to decipher the code... and this is when things became interesting :-)
So, here I am with my first obstacle: two instructions [SIZE?] and [PSIZE]. “Very well, this should be somewhere in the user handbook” - I said to myself. I decided to search on what is here called TOS... and found no reference whatsoever on the entire manual. What the heck??? I googled them and I got the same fruitless result. Is this some kind of arcane, undocumented and obscure code only accessible to the initiated? I began to wonder. Back to TOS, I found a manual written by Ángel. Ah ha! And I see a program using the dreaded codes, both of them! And also my next significant clue: XROM 25, A6:6C. So, this is an extended rom thing and I had to look for the number 25!
Back to the museum, I look for this rom on the software>xrom section, finding several rom extensions implementing these two instructions, including an extended functions module identified with number 25! But there is no description of these instructions and even if I already had a little idea of what they do, I wanted to know how they really work. The next step was to look into the HP41 section of the museum and see that this module has a product number: the 82180A, and therefore there should be a user manual. So back again to TOS and voilŕ, finally the Holy Grail and reward of this embarrassing quest: the 82180A extended function/memory module manual, somewhat buried in the standard peripheral section of the library with the descriptions I was longing for.
So, I can finally advance to line 11 :-)
- After finishing writing these lines I will buy the museum DVD. It is really a must. Until now, I was satisfied with CDs I and II which contains the majority of manuals for my collection.
- It was a really fun Saturday morning activity ...
- But, I will never post a so shameful confession again!
Have a nice weekend!
Edited: 12 Nov 2011, 11:26 a.m.