The Museum of HP Calculators

HP Forum Archive 14

 33s Memory is 12 kB not 31Message #1 Posted by bill platt (les Estats Unis d'Amerique) on 16 June 2004, 1:44 p.m. Hi, The 33s is not as efficient with memory as the 32s was. Taking the 5 degree polynomial root finder program suite for comparison, the 32s used 268.5 bytes, whereas the identical program in the 33s takes 717 bytes. So, if you do the maths, you should reduce the 31plus kb to 12 kB. Or, all memory is not created equal.

 Re: 33s Memory is 12 kB not 31Message #2 Posted by Vieira, Luiz C. (Brazil) on 16 June 2004, 5:15 p.m.,in response to message #1 by bill platt (les Estats Unis d'Amerique) Hi, Bill; I don't have an HP32S (neither an SII) but I observed that the HP33S is a "byte eater" when writing programs. I guess this is because of internal addressing/coding, or structural organization. I remember reading one of Hidalgo's papers (if I am not wrong, it was his) about the HP12C addressing and the new functions plus possible steps (GTO with three digits instead of two). It's easy to "mask" memory used information ([g][MEM]) in this case, I mean, in the HP12C is easy to show an amount of bytes used in MEM that's not exactly the amount actualy used. I'd not be surprised if there are two-byte functions in the HP12C that are counted as one (the O.S. should simply count the number of steps used by "programs" and show the difference of existing, "masked" memory). I guess the HP33S uses more than 12 bits (1.5 bytes) per instruction. And we must count also equations/functions used in programs. BTW, was it possible in the HP32SII? I mean, insert equations/functions as a program step? Oh, yes: I remember reading Gene's post about using as many steps with flags as necessary to bypass a sequence of steps and, with this, reduce the number of used labels in one single program. If the sequence can be written as an expression, it would even be better, like: (consider LBL C for this program) ```... C0008 FS? 4 C0009 (any expression) C0010 FC? 4 C0011 (another expression)``` It woud also save memory. I think the HP33S is getting some considerable status: as it is some sort of "non-HP" instead HP calculator and has some weird behavior, at least it's taking some of our time to explore and discuss. I take this as good for us all. We're "explorers" again. "Terra incognita", "Undiscovered Country", whatever! Cheers. Luiz (Brazil) Edited: 16 June 2004, 5:17 p.m.

 Re: 33s Memory is 12 kB not 31Message #3 Posted by bill platt on 16 June 2004, 5:59 p.m.,in response to message #2 by Vieira, Luiz C. (Brazil) Hi Luiz, Nice to hear from you directly. Someone (Paul Brogger maybe?) figured out the memory usage way back in the beginning of the 33s era--there is a post somewhere. Quote: BTW, was it possible in the HP32SII? I mean, insert equations/functions as a program step? Yes, this functionality was developed in the 32sii. Quote: If the sequence can be written as an expression, it would even be better, like: (consider LBL C for this program) ... C0008 FS? 4 C0009 (any expression) C0010 FC? 4 C0011 (another expression) You are absolutely right about this---the use of expressions within programs is a powerful tool--it is sort of like a different way to do what is done in RPL, where an algebraic expression may be evaluated inside an RPL program. And it is also potentially more readable. Especially interesting is the use of solve *inside* a program----I'll have to buy another 33s (or a 32sii) to look at that--as I have lost mine already! I do not think you can "solve" an equation inside a program, however--unless it is part of a labelled subroutine (so therefore no labes saved). Try some experiments! Because label-saving is such a big deal, the best way to use up memory on the 33s is to make as many of your programs as possible into equations in the "equation list." A good example is the TVM equation. No need to program it and waste a label. In other words, save the programming memory space for only those tasks which are either Loop/conditional dependent, or are merely "typing aids" in (Wlodek's terminology---for instance converting feet to meters). One interesting limitation on equations in the 33s which did not exist in the 32sii is that you are only allowed 256 (or is it 255?--can't remember exactly) characters in an equation. The 32sii had no such limitation (but of course with only just under 400 bytes, you were not likely to get there anyway! The other limitation which I find extraordinarily unfortunate is that you are still not able to edit an equation without backspacing to the error! I used a 32sii ffrom 1996 up to this year, as my primary (and I really underutilized it--as it replaced an 11c and I used the computer or my pencil and paper for everything that I couldn't do on the 11c). Then I sold them for a profit to desparate test takers, and have more than spent the proceeds on too many hp calculators! I now have a 32s which I am really enjoying---no equations, yet it is a much cleaner more logical keyboard! And interestingly, there is no Rup button on it---only an Rdown (the 32sii has both functions). Quote: I think the HP33S is getting some considerable status: as it is some sort of "non-HP" instead HP calculator and has some weird behavior, at least it's taking some of our time to explore and discuss. I take this as good for us all. We're "explorers" again. "Terra incognita", "Undiscovered Country", whatever! This is why I enjoyed the Algebraic mode--because it was something to figure out! (It is not proerly documented--and there have been two different versions shipped). Best regards, Bill