Comparing 15c ans 35s

[Jeff_Kearns]

(02-14-2015 12:11 PM)Jlouis Wrote:  15c is more robust, has a better keyboard and the landscape format and size are better, IMHO. The 33s is faster, 2 line display and some good functions handy on the keyboard.

I prefer the 15c.

This discussion comes up every once in a while and it is nice to see the new forum addressing these questions. An almost identical thread was started in 2003 concerning the 15C vs the 32sii, and one of the contributors - Valentin Albillo, wrote the following:

"Here are a few reasons why the HP-15C is better than the HP32S/SII:

> smaller, the most pocketable of all bar none.
> much more rugged and solidly built, will stand a lot of abuse without flinching, wears very little with age even in the worst environments. So far, 20 years up and counting ...
> clearer, very contrasty, segmented display, ideal for optimum visibility and legibility of numbers and numeric computations, like it should for a pure *calculator*.
> batteries last for *decades*, even under daily use.
> the 32S/SII usually gathers a lot of dust under the display, which is very annoying and extremely difficult to remove, if at all. The 15C doesn't, even if using it in extremely dusty places (e.g.: a year at the Sahara desert)
> *much* better keyboard, with classic molded keys, Helvetica font lettering, [f] and [g] keys, large ENTER key, ..., never failing to register a key or provide tactile feedback.
> (this does not apply to the 35S) *much* larger RAM, besides most instructions take 1 byte. The 32S is absolutely *starved* for RAM, and instructions take 1.5 or more bytes, so it uses it fast. For instance, the number 123 in a program takes just 3 bytes on the 15C, 9.5 bytes on the 32S !! This means that any given amount of RAM (say 200 bytes) will store much more instructions in the HP-15C than it does on the 32S/SII, so further compunding the problem.
> complete matrix functionality, including multiple matrices in memory, perfectly integrated with RPN: you can have matrices on the stack, on registers, do all kind of arithmetic functions with them, solve systems of linear equations with a single instruction, special functions to deal with complex matrices, etc, etc.
> complete complex number functionality, perfectly integrated with RPN: *all* standard functions work with complex numbers, including hyperbolics and inverse hyperbolics, 5-level parallel RPN stack, including LAST X, etc.
> the 15C can have up to 67 registers available for data. The 32S can have only 26 at most.
> the 15C has all 12 comparison tests, the 32S doesn't (he was wrong about this, certainly as far as the 32sii and 35s are concerned). Many other instructions have test capabilities in programs as well, such as SOLVE, INTEGRATE, and a number of matrix operations.
> the 15C does have GTO (i) and GSB (i), for indirect branching, plus if the I register contains a negative number, it will perform rapid branching to *any* program *step*, no label needed. The 32S/SII has no such capabilities at all, which further cripples programming.
> The Hp-15C oozes quality. Every feature, from the extremely well-thought keyboard layout, to the microcode implementation of all its many functions, has been designed with utmost care, no compromises. For instance, the HP-15C overloads operators to maximize every key's functionality. Take the [+] key, for example; would you believe it has *seven* different functionalities ? Namely:
1. to add up two real values
2. to add up two complex values
3. to add up two matrices
4. to add up some scalar to all elements of a matrix
5. to directly add up a value in the display to a register (STO+)
6. to directly add the value of a register to a number in the display (RCL+)
7. to specify a certain diagnostic test ([ON]-[+])

That's just the tip of the quality iceberg. The numerical algorithms are the best, most accurate in the world. The USER modes for entering/displaying matrix elements, with autoincrement, do-if-true capability, will even preview the name of the matrix and indexes of the affected element as long as the relevant key is kept pressed, performing the operation upon release or nulling it out upon timeout, etc, etc.

On the other hand, the HP32S/32SII (and by extension, the 35S) is a machine full of compromises, with some good features intermixed with other half-baked ones or even frankly crippled. It's not an all-round product, at all. Just look at the overloaded [+] key example above: to add two complex numbers on the 32S, you must use an ad-hoc function for the task, CMPLEX +, as the obvious choice, the [+] key on its own, won't do it.

The bottom line: the HP-15C is probably the best pure calculator ever built, period, and owning one is both classy and expensive. The 32S (or 35S), though desirable, can't come up even close to that privileged status. It's just a fine but ultimately seriously flawed calculator. Comparing it to the 15C is kind of preposterous, the 42S is more like it."

The best way I have found to search the old forum archives is to google the key words followed by site:hpmuseum.org. In this case 15c vs 32sii