JM-15S - feedback welcome

[jwm]

(08-04-2014 06:31 AM)walter b Wrote:  A couple of nice ideas What's [beta] and [beta]^x on your keyboard? And what's the pink MOD= up there?

Beta is just the base of logarithm used for the keys that would normally be used for 10^x and LOG_10. I often need 2 instead for instance when doing information theory calculations, other times I want it to follow whatever the current base is. 16 for hex, etc. The idea is you can stick whatever you want in the Beta register and it will use that, if you set it to zero it will follow the base.

The MOD= is a register that sets the modular arithmetic field. as in, put 7 in there and all calculations will take place in the field (mod 7). This implies integral mode, and can be used to simulate specific bit widths by setting it to 2^n for some n, but can be set to any value for arbitrary modular arithmetic.

Quote:[*]You're missing two sums (xlny and ylnx) you'll need for L.R.

are they not the last two values under LSUMS or do you mean something else?
are collecting the inverses useful for a type of linear regressions as well? as in Sigma_1/x and so forth.

Quote:[*]I'd move R/S right of trigs. At its present position it looks a bit lost.

sure.

Quote:[*]Pink labels?!? Please think about another color.

Yeah, was chosen somewhat randomly because 34S green did not turn out easy to read on my inkjet printer. Will fiddle with colors, other than the gold and blue f and g of course.

Quote:[*]You wrote:

Quote:- an unlimited stack, ... A 'FILL' register is used to fill in past the end of the stack so various tasks depending on duplicating T still work.

Now what is it what you want? :-?

So, on the 15C, when you perform an operation consuming a stack value, the T register is duplicated to keep a full stack but you are limited to 4 spots. This is useful when calculating polynomials for instance. On the 50g you have an unlimited stack but it beeps annoyingly when you reach the end of it. With this I want to combine the best of both behaviors. The stack will be unlimited but when you reach the end of it instead of producing an error, it will pretend it has an infinite number of whatever value is in FILL on the stack. so, put zero in FILL and it will be zeros all the way down.

Quote:[*]You wrote:

Quote:- an unlimited stack, meaning I can do without shortcut functions, [2][y^x] behaves the same as [f][x^2].

I don't see the link. :-?

On some HPs like the 35s, it has keys like [f][x^2]. as in, squaring underneath a shift key. However, it also have a top level y^x, making the x^2 redundant. [2][y^x] is exactly as many keystrokes as [f][x^2]. The only reason for it to exist is that on a limited stack machine, [2][y^x] will clobber the 'T' value. with an unlimited stack this isn't an issue. I added the top level \sqrt{x}{y} to make square roots easy in the same way.

So, I don't have R+ and R-, but i was thinking of adding 'PUSH' and 'POP' which will take the current x value and push it onto an alternate stack or pop a value off of it. This will allow you to traverse up and down the stack like with r+ and r- but not rely on the wraparound rotation behavior. you would just be shuffling values to the alternate stack and back to the primary one.

John