WP43 News

[Walter]

There are many users who have operated the classic RPN calculator with two thumbs. With this type of operation and with the one-finger version for right-handers, the lower left button is ergonomically less accessible than the + button on the "classics" Position.

Thanks. May be. At least this is an ansatz. But one operation has to go bottom left, and according to your story HP chose divide.

If this really was the reason, why on earth did they also swap plus and minus? They could have put simply / × − + (bottom up) in the left column, couldn't they? Are there any grey-haired troupers supporting Peet's story?

A week has passed and just one person has supported Peet's story (newspeak: narrative). This doesn't sound good for a rational base of / × − + (bottom up) or even / × + − in the left column of pocket calculator keys. Anyone else?

Another week has passed without anybody standing up and stating reasons for the HP-35 way of sorting the basic arithmetic operators. Looks like this way is DAAD (dead as a doornail). Thus, we'll stay with + − × / below ENTER.

[Walter]

Looks like we can expect a lot more program memory than I thought so far. Program steps vary in length so exact numbers are impossible to calculate. But present data indicate that some 20 000 steps in RAM are possible, with up to 10 000 steps in one program. Program specific step counting (like in HP-42S) is supported:
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[Walter]

(There seems to be a limit of 3 files per post so I've to continue with a new post:)
See some local registers and flags in action, also using indirect addressing:
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[Walter]

For you who want to play and test over the holidays, there is a new wp43s.exe available in https://gitlab.com/Over_score/wp43s/-/t ... 20binaries

Enjoy!

[Walter]

The Christmas update of the WP43S Owner's Manual is available at a gitlab close to you.

Merry Christmas!

[Walter]

Meanwhile, program step specific byte counting was dropped:
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(actually not the counting but the display of bytes per step).

[Walter]

Two days ago, in a forum in the wild wild west, Valentin Albillo set the following task:

Let's partition 2021 into a set of positive integer numbers that add up to 2021. Find the set of such numbers whose product is maximum, and output that maximum in all its full glory.

For instance, we could have 2021 = 1 + 1 + ... + 1 (2021 1's) and their product would be 1 x 1 x ... x 1 = 1, which doesn't quite cut it. We could also have 2021 = 137 + 682 + 1202 and their product would be 137 x 682 x 1202 = 112307668, which is much better but still far from the maximum as well.

The maximum product must be the volume of a hypercube in n-dimensional space, as far as possible under the conditions set. Luckily I had got my WP43S handy and tried a bit. Result: maximum volume is achieved for (2021/743)^743. The 743 edges of the hypercube must be either 2 or 3 long. 743x3 = 2229 which are 208 too much. Thus, 535 edges must be 3, and 208 must be 2, and the volume is 3^535x2^208.

But is this really the maximum volume? Let's try with 1 dimension less: 742x3 = 2226 which are 205 too much. Thus, 537 edges must be 3, and 205 must be 2, and the volume is 3^537x2^205. This is the previous volume times 9/8.

So I continued reducing dimensions in larger steps until reaching 674 parts. 674x3 = 2022 which is only 1 too much. Thus, 673 edges must be 3, and 1 must be 2, and the volume is 3^673x2. Keying this in the WP43S simulator, you get a long integer with 321 digits. The exact value is

2532995521886826292328149655127793939711079648569980904926813070890600257967555788084132383052323458136675408253781974882864255212314264505911807500659338824573345556963262198232747186628808383273213581619626233679533487706060253494981896112664520885716630483899029142003916544644957076791520721759240671604739781810307846

Just a little demonstration what can be done...

[pauli]

Finally, acceptance of long integer arithmetic


Pauli

[Walter]

Finally, acceptance of long integer arithmetic

743-dimensional space is quite out of touch compared to linear regression, for instance. Pure and applied math... the cream and the cake... IMHO.

[DA74254]

Aaand now, I'm just waiting for the '43s to calculate the cube root of Grahams Number