|Re: Why not a stack settable to 8 levels max.?|
Message #46 Posted by Antoine M. CouŽtte on 18 Dec 2007, 7:24 a.m.,
in response to message #45 by Walter B
Thank you again for your reply Walter.
I fully buy your FILL and STSIZE instructions which seem to very nicely respond to my concerns about 4/6/8 level stacks Program Compatibility ( still 1 byte instructions :-)) ? ) .
My understanding of the stack is very simple: a temporary storage where I push all the intermediate results until I need them, allowing me to forget to take care of closing parentheses, operator precedence and the like. x<>y is the only "stack management instruction" I really need and often use.
It then looks that - as every single Programmer/User in the vast majority of cases - you do not use the systems possibilities to their full extent in every single direction.
The very same holds true for me : I have almost never used LN , EXP or LOG in my Astronomical or Aircraft Fuel Management Software since I simply do not need these functions for my usual applications. This is certainly not a reason to "dump" such functions which are a must for a number of other Programmers/Users.
By comparison with the above :
FIRST I will certainly not question the way you have used the RPN stack,
SECOND, I would only notice that you look satisfied with a " reduced set " of Stack Management Instructions. Therefore, a more comprehensive " tool set " would be of little interest to you. However, should this be a reason to deprive other Users/Programmers from having a more comprehensive set of Stack Management Functions available at fingertip to manage their 6 or 8 level RPN stack ?
For the nerds, we still have RPL ;-)
This is very true, but unfortunately, RPL - if you mean here the HP48GX programming User language - is much less intuitive than RPN. After a few days of hard learning, including Richard Nelson's early HP28/48 courses and after studying Bill Wickes's Book on HP28/48, I realized that just after a few weeks of non-practice, I would forget almost everything.
The RPN concept is so much easier than RPL for me in this respect : just 5 numbers in the stack. Play with them through all familiar " operators " learnt at school ( +, - , x , / , SIN, ASIN, EXP , LN, .... ) and simple Stack Operators. Should you resume working on RPN after months, or more : here again you are immediately "home", even if such "home" does not have - and by far - the latest and most modern commodities.
This is why I stick to RPN on a handheld.
Otherwise, instead of RPL even on a handheld, I would rather go into learning BASIC for a Handheld. It should not be too much difficult since I did practice FORTRAN2 ... many moons ago !!. Why BASIC ? Simply because Valentin Albillo so superbly gives us here demonstrations of the power of this language.
And, by the way there are also superb HP71 Emulators on the Market both for Laptops and for Handhelds.
In other words, and to summarize all the above :
If had to use a 8 level stack RPN system with only the following stack management functions ( X<>Y, X<> , RUP and RDOWN ) , I would certainly feel deprived from so many goodies ... exactly like when I first tried a plain HP41C : 49 RAM Memories Registers( was it 49 actually ??? I do not remember .. ), while soon after I eventually discovered that its processor can address 319 RAM memories, as well as 600+ XMEM Registers, not to mention that HrastProgrammer can address over ... 3000 RAM Memory Registers in his HP41X/Y/Z Emulator.
Or, to make it short ...
Having only the " X<>Y, X<> , RUP and RDOWN " instructions to manage an 8 level or even a 6 level RPN stack would be for me like driving A PORSCHE SportsCar with only a 2 US Gallon Fuel tank,
or, even worse ...
: Flying a B777 with only a 15 Ton Fuel tank!
... Like the plain HP41C story hereabove, this can be Very Frustrating.
PS : I almost never have had so much time for "entering" the Forum like I have done in the past few days. Just simply because now I am on a 3 Day Alert Status, away from home, counting grains of sand in Jeddah Saudi Arabia, and awaiting to fly my B757.
Edited: 18 Dec 2007, 1:44 p.m. after one or more responses were posted