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HP 35s Scientific Calculator
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very good, but some room for improvement
(4 out of 5) by StevieQ on Jan 16, 2008 (Castro Valley, CA United States)I am a diehard RPN and HP calculator fan. I bought this calculator for the PE exam. HP calculators I've owned include HP41c, HP42s, HP12c, HP17BII, HP19BII, and HP33s. The HP35s is basically an HP33s with most the ergonomic design flaws and quality issues of the HP33s fixed, along with a few added enhancements. It's what the HP33s should have been in the first place. But, along the way, it also introduces a few design flaws of its own.
Obvious pluses: The keys on the HP35s feel almost like the ultra high quality keys on the HP41c, not entirely there because the ones on the HP35s are flatter and have less travel distance, but very close. However, unlike those on the HP41c, some of the secondary colors on the keys are only painted on. How long would the paints last? It comes with a super nice semi-rigid vinyl case. The LCD display is fragile, but it seems to be dust-proof and has excellent contrast. The built-in metric/imperial conversions and constants library are also nice. One major enhancement over the HP33s is the ability for a program to refer to a line number instead of a label name during conditional branching. This feature allows the writing of programs that don't use up a lot of the precious program labels. The equation solver is quite powerful. It comes with built-in equations for solving 2x2 or 3x3 simultaneous equations.
Obvious minuses:
There are only 26 single alphabet program labels and only 26 variables, severely limiting the number of programs one can store, considering the somewhat large 30kB memory available(the HP42s only has 8kB). The manual has a good number of useful programs, but in reality one can store only a few of these programs on the calculator at a time due to the 26 program label limit. I can store more programs on the HP42s even though it only has 8kB of memory. In actual use, most of the 30kB on the HP35s will go untapped.
It's a shame HP chose not to include multi-letter alpha-numeric capability as they did on the HP41c and HP42s. Instead of labeling a program that calculates the time value of money using a single letter such as "T", I'd much rather be calling the program "TVM" or "MONEY" or something easy to remember. The same one-letter restriction applies also to variable names. The listed battery life is on the short side. Two hours of use per day will last the batteries only about 9 months.
Whereas the HP42s offers four types of curve-fitting and has capability to choose one with the best fit, the HP35s offers only linear regression. Also, unlike the HP42s, the HP35s doesn't have any built-in matrix capability to evaluate determinants, inverses, although it does have built-in 2x2 or 3x3 simultaneous equation solving ability as mentioned earlier. You can program all these missing capabilities in but you'll use up many of the precious 26 program labels in a hurry.
The STO key which I use very often is now subordinated, requiring a shift key, whereas the "Mode" key which I seldom use is primary.
The display has much more glare than other HP models I've owned.
Although I will almost never use the algebraic mode except when writing equations, I must mention that its implementation on the HP35s is clumsy. On other algebraic calculators I grew up with, the number precedes a function key (such as COS, 1/x, log) and the function is executed as soon as the function key is pressed. In other words, even though they are algebraic calculators, their function keys work in postfix or RPN mode.
The key sequence is
45
COS
The value of 0.707 is displayed as soon as the COS key is pressed. It's very simple and intuitive. This is also how the functions work on the HP33s. But, surprise, this ain't how it works on the HP35s!
On the HP35s, you have to start by first pressing the function key and then punch in the number and then press the Enter key to get the value.
The key sequence is
COS
45
ENTER
The ENTER key works as the equal sign key in algebraic mode on the HP35s. Hitting the ENTER key now becomes mandatory to get an answer from just about any operation. Although this peculiar algebraic approach may make sense when writing equations, it's highly cumbersome when doing calculations on the fly, especially for someone used to the keystroke efficiency of RPN.
I sometimes scratch my head trying to figure out why for the last 10-15 years HP kept churning out mediocre calculators, with each new one worse than the previous one. Why mess with winning designs and dumb them down to the level of TIs and Casios? Yes, the money is where the masses are and the masses are the high school and college crowd and they use predominantly TIs and Casios. Then it dawned on me that the sales execs, designers, programmers, engineers also have to somehow justify their existence by rolling out new models and discontinuing older but superior models. The HP35s seems to be a step to halt the march toward mediocrity. Does it succeed? Yes, mostly. Although the build quality is good, it certainly could have been designed better.
Even though the STO key is now subordinated, the HP35s fills the need for basic everyday number crunching due to its ergonomic form factor and ease of use combined with a reasonably rich set of functions. The HP50g fills the need for heavyduty scientific/engineering use but is too clumsy for everyday basic number crunching.
I'm sure as I use this calculator more, I will see more of both the pluses and minuses. And, if I were to rate this calculator in comparison with any Casio or any TI, I would give it 10 stars if I could. But I rate it in relation to what I expect an HP calculator should be and so I rate it 4 stars. If the HP35s came with more program labels and variables than just 26 of each (A to Z), multi-letter alpha-numeric data entry capability, matrix capability up to [5x5], 4 types of curve fits and best of fit, primary STO and RCL keys, I would rate it 5 stars.
Obvious pluses: The keys on the HP35s feel almost like the ultra high quality keys on the HP41c, not entirely there because the ones on the HP35s are flatter and have less travel distance, but very close. However, unlike those on the HP41c, some of the secondary colors on the keys are only painted on. How long would the paints last? It comes with a super nice semi-rigid vinyl case. The LCD display is fragile, but it seems to be dust-proof and has excellent contrast. The built-in metric/imperial conversions and constants library are also nice. One major enhancement over the HP33s is the ability for a program to refer to a line number instead of a label name during conditional branching. This feature allows the writing of programs that don't use up a lot of the precious program labels. The equation solver is quite powerful. It comes with built-in equations for solving 2x2 or 3x3 simultaneous equations.
Obvious minuses:
There are only 26 single alphabet program labels and only 26 variables, severely limiting the number of programs one can store, considering the somewhat large 30kB memory available(the HP42s only has 8kB). The manual has a good number of useful programs, but in reality one can store only a few of these programs on the calculator at a time due to the 26 program label limit. I can store more programs on the HP42s even though it only has 8kB of memory. In actual use, most of the 30kB on the HP35s will go untapped.
It's a shame HP chose not to include multi-letter alpha-numeric capability as they did on the HP41c and HP42s. Instead of labeling a program that calculates the time value of money using a single letter such as "T", I'd much rather be calling the program "TVM" or "MONEY" or something easy to remember. The same one-letter restriction applies also to variable names. The listed battery life is on the short side. Two hours of use per day will last the batteries only about 9 months.
Whereas the HP42s offers four types of curve-fitting and has capability to choose one with the best fit, the HP35s offers only linear regression. Also, unlike the HP42s, the HP35s doesn't have any built-in matrix capability to evaluate determinants, inverses, although it does have built-in 2x2 or 3x3 simultaneous equation solving ability as mentioned earlier. You can program all these missing capabilities in but you'll use up many of the precious 26 program labels in a hurry.
The STO key which I use very often is now subordinated, requiring a shift key, whereas the "Mode" key which I seldom use is primary.
The display has much more glare than other HP models I've owned.
Although I will almost never use the algebraic mode except when writing equations, I must mention that its implementation on the HP35s is clumsy. On other algebraic calculators I grew up with, the number precedes a function key (such as COS, 1/x, log) and the function is executed as soon as the function key is pressed. In other words, even though they are algebraic calculators, their function keys work in postfix or RPN mode.
The key sequence is
45
COS
The value of 0.707 is displayed as soon as the COS key is pressed. It's very simple and intuitive. This is also how the functions work on the HP33s. But, surprise, this ain't how it works on the HP35s!
On the HP35s, you have to start by first pressing the function key and then punch in the number and then press the Enter key to get the value.
The key sequence is
COS
45
ENTER
The ENTER key works as the equal sign key in algebraic mode on the HP35s. Hitting the ENTER key now becomes mandatory to get an answer from just about any operation. Although this peculiar algebraic approach may make sense when writing equations, it's highly cumbersome when doing calculations on the fly, especially for someone used to the keystroke efficiency of RPN.
I sometimes scratch my head trying to figure out why for the last 10-15 years HP kept churning out mediocre calculators, with each new one worse than the previous one. Why mess with winning designs and dumb them down to the level of TIs and Casios? Yes, the money is where the masses are and the masses are the high school and college crowd and they use predominantly TIs and Casios. Then it dawned on me that the sales execs, designers, programmers, engineers also have to somehow justify their existence by rolling out new models and discontinuing older but superior models. The HP35s seems to be a step to halt the march toward mediocrity. Does it succeed? Yes, mostly. Although the build quality is good, it certainly could have been designed better.
Even though the STO key is now subordinated, the HP35s fills the need for basic everyday number crunching due to its ergonomic form factor and ease of use combined with a reasonably rich set of functions. The HP50g fills the need for heavyduty scientific/engineering use but is too clumsy for everyday basic number crunching.
I'm sure as I use this calculator more, I will see more of both the pluses and minuses. And, if I were to rate this calculator in comparison with any Casio or any TI, I would give it 10 stars if I could. But I rate it in relation to what I expect an HP calculator should be and so I rate it 4 stars. If the HP35s came with more program labels and variables than just 26 of each (A to Z), multi-letter alpha-numeric data entry capability, matrix capability up to [5x5], 4 types of curve fits and best of fit, primary STO and RCL keys, I would rate it 5 stars.
86 of 87 people found the following review helpful:
Best Scientific Calculator Available Today
(5 out of 5) by David Simpson on Sep 5, 2007 (Laurel, MD USA)This is a very nice high-quality scientific calculator from HP. The overall design and capabilities are similar to the HP 32SII (equation solver, unit conversions, etc.), but with several enhancements.
Like many recent HP models, this calculator can work in either RPN or algebraic mode, but I use only RPN. The keyboard layout has been well thought out, with most functions being quickly available directly from the keyboard and a few lesser-used functions available through menus. The keyboard has a traditional HP layout and colors, and the keys have a nice positive feel. A very thorough and well-written printed manual is included.
A new feature with this model is that each level in the four-level stack may hold a real number, complex number, or 2- or 3-element vector. Complex numbers may be entered very simply using the "i" key (or "theta" key for polar form); vectors are entered using square brackets. This design makes it very easy to manipulate complex numbers and vectors.
The calculator includes 30 kB of memory, which is enough for over 20,000 program steps. There are 26 main memory registers (A-Z), six statistical registers, and 800 more memory registers available through indirect addressing. Another new feature of this model is TWO indirect registers, (I) and (J).
A few cons: With previous HP calculators, there was a shortcut for entering exact powers of 10: for example, 10,000 could be entered as "E 4". For some reason HP has dropped that feature on the 35S, so you now have to enter "1 E 4". Not a major drawback, but kind of annoying since I used that shortcut a lot on previous models. Another nit is that the function to convert HMS to decimal hours is labeled HMS-> instead of ->H, which I haven't gotten used to yet.
Overall, the HP 35S is a very well-designed calculator, and I would not hesitate to recommend it as the best general-purpose scientific calculator available today. In fact, I bought three (for home, work, and school).
Like many recent HP models, this calculator can work in either RPN or algebraic mode, but I use only RPN. The keyboard layout has been well thought out, with most functions being quickly available directly from the keyboard and a few lesser-used functions available through menus. The keyboard has a traditional HP layout and colors, and the keys have a nice positive feel. A very thorough and well-written printed manual is included.
A new feature with this model is that each level in the four-level stack may hold a real number, complex number, or 2- or 3-element vector. Complex numbers may be entered very simply using the "i" key (or "theta" key for polar form); vectors are entered using square brackets. This design makes it very easy to manipulate complex numbers and vectors.
The calculator includes 30 kB of memory, which is enough for over 20,000 program steps. There are 26 main memory registers (A-Z), six statistical registers, and 800 more memory registers available through indirect addressing. Another new feature of this model is TWO indirect registers, (I) and (J).
A few cons: With previous HP calculators, there was a shortcut for entering exact powers of 10: for example, 10,000 could be entered as "E 4". For some reason HP has dropped that feature on the 35S, so you now have to enter "1 E 4". Not a major drawback, but kind of annoying since I used that shortcut a lot on previous models. Another nit is that the function to convert HMS to decimal hours is labeled HMS-> instead of ->H, which I haven't gotten used to yet.
Overall, the HP 35S is a very well-designed calculator, and I would not hesitate to recommend it as the best general-purpose scientific calculator available today. In fact, I bought three (for home, work, and school).
51 of 53 people found the following review helpful:
Not a bad calculator, for a change
(4 out of 5) by Bob Manson on Oct 16, 2007 (Berkeley, CA United States)The 35s is the most interesting calculator HP's produced in a while. While I'm sure their intended market is the legions of dedicated HP users, even if you're not a lover of antiques you should give it a look.
A definite improvement on the 32sII, and in general I would recommend it over purchasing an overly-expensive used HP. While the hardware isn't quite as nice the 35s should have a much longer battery life, and has more than enough memory to hold any reasonable number of programs.
It's physically larger than a 32s and it's not really "pocket-size". Yet it's not that big compared to modern scientifics and the larger display is worth it.
It feels very solid, except for a battery door which pops off a bit too easily. Lithium coin batteries are so much easier to deal with than watch batteries that I'll happily accept the tradeoff.
The keyboard is slightly soft compared to older HPs but that's been easy to get used to. It has a definite click, good-sized keys with a large Enter key, and should seem quite familiar to HP users. Unfortunately it uses painted-on key symbols which I suspect will show wear rather quickly.
Crisp display, easily readable from practically any angle. A huge improvement over the LCDs in HP's older models.
It has RPN and algebraic modes, as well as an EQN key which allows algebraic entry while in RPN mode. Most keyboard functions have an EQN/ALG counterpart, and while algebraic formulas can be used in programs you'll still need to use RPN for conditionals and loops.
The excellent mixed-base number support is a pleasant surprise. In algebraic mode you can easily enter a calculation in mixed bases without changing the current base. (This mostly works in RPN, but there's no way to enter hex A-F without switching modes.)
Programming is similar to the 32s and much of the manual is identical--the only major change is additional memory. The 35s' overloaded keys and simple design make programming much easier than an RPL-based calculator like the 49g+.
Why did it only get 4 stars? Two issues:
No I/O. Being able to backup memory would make me a little happier and I've come to expect this from a modern programmable.
And, RPN programs generally run only about as fast as on the 32s, making its programmability less useful than otherwise. After 15 years I expected to see at least a factor of five speed increase.
In short: I like it, and I think you will too. In terms of price and ease of use it can't compete with, say, the Sharp EL series. (The new HP 10s is a real contender there.) But the HP 35s' programming capabilities set it apart from any of the inexpensive scientifics. If you'll take the time to learn RPN, you'll find writing programs is easier and more convenient than writing the same thing in a BASIC-like programming language.
A definite improvement on the 32sII, and in general I would recommend it over purchasing an overly-expensive used HP. While the hardware isn't quite as nice the 35s should have a much longer battery life, and has more than enough memory to hold any reasonable number of programs.
It's physically larger than a 32s and it's not really "pocket-size". Yet it's not that big compared to modern scientifics and the larger display is worth it.
It feels very solid, except for a battery door which pops off a bit too easily. Lithium coin batteries are so much easier to deal with than watch batteries that I'll happily accept the tradeoff.
The keyboard is slightly soft compared to older HPs but that's been easy to get used to. It has a definite click, good-sized keys with a large Enter key, and should seem quite familiar to HP users. Unfortunately it uses painted-on key symbols which I suspect will show wear rather quickly.
Crisp display, easily readable from practically any angle. A huge improvement over the LCDs in HP's older models.
It has RPN and algebraic modes, as well as an EQN key which allows algebraic entry while in RPN mode. Most keyboard functions have an EQN/ALG counterpart, and while algebraic formulas can be used in programs you'll still need to use RPN for conditionals and loops.
The excellent mixed-base number support is a pleasant surprise. In algebraic mode you can easily enter a calculation in mixed bases without changing the current base. (This mostly works in RPN, but there's no way to enter hex A-F without switching modes.)
Programming is similar to the 32s and much of the manual is identical--the only major change is additional memory. The 35s' overloaded keys and simple design make programming much easier than an RPL-based calculator like the 49g+.
Why did it only get 4 stars? Two issues:
No I/O. Being able to backup memory would make me a little happier and I've come to expect this from a modern programmable.
And, RPN programs generally run only about as fast as on the 32s, making its programmability less useful than otherwise. After 15 years I expected to see at least a factor of five speed increase.
In short: I like it, and I think you will too. In terms of price and ease of use it can't compete with, say, the Sharp EL series. (The new HP 10s is a real contender there.) But the HP 35s' programming capabilities set it apart from any of the inexpensive scientifics. If you'll take the time to learn RPN, you'll find writing programs is easier and more convenient than writing the same thing in a BASIC-like programming language.
21 of 21 people found the following review helpful:
Welcome back HP
(4 out of 5) by Sidney Cave on Sep 29, 2007 (Orlando, FL)I have been using HP's low to mid priced calculators since I bought an HP21 back in 1977. HP lost its vision in recent years with their calculators, abandoning RPN in their lower priced models and producing disasters like the HP6s and the HP33s. The HP35s is a definite sign of improvement. In spite of the gripes I list below, I consider this a good calculator I look forward to the HP35sII.
What they got right:
Good physical design, with good key lettering and key action. Not like their recent designs that are about style instead of clarity and ease of use. Similar to some of HP's older (and better) calculators. The key action is still not quite up to my favorite, the HP32s.
Errors:
The values for COS and TAN calculations near 90 degrees are incorrect in the last few digits.
Deficiencies:
The exponents of displayed values are off screen when the DISPLAY mode is set to ALL or using "ENG ->" or "<- ENG".
You must use 3 keystrokes to enter "h", "b" or "o" after non-decimal number entry. You should NEVER need to do this to any number being entered in the base of the selected mode. I can see were it would be handy for entering nummbers in an alternate base, but only then.
Keys for hex digits A through F are unlabeled in RPN mode and require two keystrokes in algebraic mode - bad design.
The thousands separators do not appear during digit entry; only after ENTER or an operation do they appear. This worked on older HP calculators.
What they got right:
Good physical design, with good key lettering and key action. Not like their recent designs that are about style instead of clarity and ease of use. Similar to some of HP's older (and better) calculators. The key action is still not quite up to my favorite, the HP32s.
Errors:
The values for COS and TAN calculations near 90 degrees are incorrect in the last few digits.
Deficiencies:
The exponents of displayed values are off screen when the DISPLAY mode is set to ALL or using "ENG ->" or "<- ENG".
You must use 3 keystrokes to enter "h", "b" or "o" after non-decimal number entry. You should NEVER need to do this to any number being entered in the base of the selected mode. I can see were it would be handy for entering nummbers in an alternate base, but only then.
Keys for hex digits A through F are unlabeled in RPN mode and require two keystrokes in algebraic mode - bad design.
The thousands separators do not appear during digit entry; only after ENTER or an operation do they appear. This worked on older HP calculators.
25 of 26 people found the following review helpful:
A Step in the Right Direction
(3 out of 5) by anonymous on Jan 4, 2008 (Colorado, U.S.A.)I bought the original HP-35 back in 1973, when it cost $395. The "new" HP-35s is better in many ways, but it still misses as a direct replacement for that classic calculator. One of the design goals of the original was that it had to fit in a shirt pocket, and it did. Oddly, the new version is larger than the original, but it does weigh less. HP made the new keyboard larger with larger keys, but IMO the old HP-35 keyboard was easier to use because it was more legible and less crowded. The HP-35s is programmable, but it has no way to store or transfer large user-created programs off of the calculator. That is the main reason I didn't rate it higher than three stars.
I'm glad to see HP making RPN the primary entry mode again. Maybe they'll follow this model with a "new" version of the HP-45 and add a USB port for data and program transfers.
Post Script 2-18-08
I've now had the calculator for a couple of months and find its annoyances outweigh the advantages. The keyboard's poor legibility and odd layout frustrate me every time I use it, and simple functions like clearing a register or a syntax error require multiple keystrokes -- arrrggg! My trusty and worn HP15C is back out of the drawer. Adios HP35s.
I'm glad to see HP making RPN the primary entry mode again. Maybe they'll follow this model with a "new" version of the HP-45 and add a USB port for data and program transfers.
Post Script 2-18-08
I've now had the calculator for a couple of months and find its annoyances outweigh the advantages. The keyboard's poor legibility and odd layout frustrate me every time I use it, and simple functions like clearing a register or a syntax error require multiple keystrokes -- arrrggg! My trusty and worn HP15C is back out of the drawer. Adios HP35s.