WP31s: is the 20B keyboard really that bad?

[Dieter]

I really like the 34s, but for many everyday applications it's simply a bit too complex, so that I prefer my 35s with its more direct access to the most important functions. That's why I consider turning another 30B into a 31s.

However, the 30B with its silver faceplate does not nearly look as nice as the all black 20B. Maybe that's why the emulator skin shows an all-black calculator as well. So I wonder if a 20B could be an option. The essential difference is the keyboard – the 30B keyboard is said to be much better. But how bad is the 20B in that regard? Would I sacrifice something substantial if I flashed the much nicer, all black 20B to become a 31s?

Dieter

[Bit]

(02-01-2015 02:52 PM)Dieter Wrote:  I really like the 34s, but for many everyday applications it's simply a bit too complex, so that I prefer my 35s with its more direct access to the most important functions. That's why I consider turning another 30B into a 31s.

However, the 30B with its silver faceplate does not nearly look as nice as the all black 20B. Maybe that's why the emulator skin shows an all-black calculator as well. So I wonder if a 20B could be an option. The essential difference is the keyboard – the 30B keyboard is said to be much better. But how bad is the 20B in that regard? Would I sacrifice something substantial if I flashed the much nicer, all black 20B to become a 31s?

Dieter

The 20b's keyboard is very different, the keys don't click, their movement is completely soft. Whether that's for the better or worse is subjective but I guess most people here would consider it worse. One advantage of the 20b's keyboard is that keys not registering can be less of a problem since you get used to pressing the keys firmly. If you suspect you might prefer keys with softer movement, give it a try, that's the only way to know for sure.

There's another difference I noticed, although I cannot be sure if it's just my samples: The LCD in the 30b's seems nicer, more contrasty.

I've made some 31S calculators based on both hardware and I didn't think the 30b's looked bad at all. I'd say the silver faceplace even adds a little character. You should paint the faceplace around the keys black as Eric does in his instructional video.

Out of curiosity, which are the functions that aren't very easily accessible on the 34S and make the biggest difference to you?

[Dieter]

(02-01-2015 03:25 PM)Bit Wrote:  The 20b's keyboard is very different, the keys don't click, their movement is completely soft. Whether that's for the better or worse is subjective but I guess most people here would consider it worse.

This does not sound so bad that I should not give it a try. ;-)

(02-01-2015 03:25 PM)Bit Wrote:  There's another difference I noticed, although I'm cannot be sure if it's just my samples: The LCD in the 30b's seems nicer, more contrasty.

Hm... can someone else confirm this?

(02-01-2015 03:25 PM)Bit Wrote:  I've made some 31S calculators based on both hardware and I didn't think the 30b's looked bad at all. I'd say the silver faceplace even adds a little character.

The sourceforge 34s site links to this picture showing both versions. Now if you could choose between these two... be honest. ;-)

(02-01-2015 03:25 PM)Bit Wrote:  You should paint the faceplace around the keys black as Eric does in his instructional video.

What pen are you using for this? Staedler's permanent markers (a common brand here in Germany) usually leave a purple shine.

(02-01-2015 03:25 PM)Bit Wrote:  Out of curiosity, which are the functions that aren't very easily accessible on the 34S and make the biggest difference to you?

It's virtually every math function. Except the four basic arithmetic keys, each and every function requires at least two key presses, even the most basic ones like roots and reciprocals. The limit is in the hardware, since the keyboard has only seven rows. When I switched from my 34C to a 41C I really appreciated the additional eigth row that allowed easy one-key access to most essential functions. That's what I also like on the 35s which has become my everyday calculator. On such a device I expect basic functions like roots, powers, logs, exponential and trig functions to be accessed directly, i.e. without having to use a shift key. The 31s comes very close in this regard.

Dieter

[Bit]

(02-01-2015 04:06 PM)Dieter Wrote:  

(02-01-2015 03:25 PM)Bit Wrote:  There's another difference I noticed, although I'm cannot be sure if it's just my samples: The LCD in the 30b's seems nicer, more contrasty.

Hm... can someone else confirm this?

The picture you linked shows a similar difference, although such images can look misleading.

(02-01-2015 04:06 PM)Dieter Wrote:  

(02-01-2015 03:25 PM)Bit Wrote:  I've made some 31S calculators based on both hardware and I didn't think the 30b's looked bad at all. I'd say the silver faceplace even adds a little character.

The sourceforge 34s site links to this picture showing both versions. Now if you could choose between these two... be honest. ;-)

That picture doesn't do the 30b justice. It looks better in real life IMO. That said, it's easy to see why someone would prefer the look of the 20b, but you really need to see the finished 30b with your own eyes to be able to judge its appearance.

(02-01-2015 04:06 PM)Dieter Wrote:  

(02-01-2015 03:25 PM)Bit Wrote:  You should paint the faceplace around the keys black as Eric does in his instructional video.

What pen are you using for this? Staedler's permanent markers (a common brand here in Germany) usually leave a purple shine.

So far I've used Sharpies that are commonly available in the USA. They aren't perfectly black but the slight tint they have doesn't bother me. I'm quite certain you can find something appropriate in Germany. I also add a few layers of clear matte protective spray paint on top of the finished product (except the LCD), it not only protects the keys but further reduces the visible tint of the paint.

[walter b]

The keyboard of the HP-20b is almost Casio-like. That's not what I'm looking forward when I repurpose a calc for me. YMMV. I think the silver faceplate of the HP-30b doesn't look so bad it outweighs the keyboard - actually it looks nicer than I expected in the beginning. IIRC, there was a forum member who sprayed his HP-30b faceplate (covering the LCD window, of course) black using some plastic model paint - searching the forum may help if you're feeling you need an all black WP 31S.

And yes, there's a difference in the displays - the HP-30b LCD goes flush with the faceplate while the HP-20b LCD is slightly recessed. I don't remember a difference in appearance or contrast though.

d:-)

[matthiaspaul]

Not having opened a 20B or 30B so far, do they both use the same PCB? Would it be possible to sacrify a 30B for parts to be implanted into the case of a 20B?

Greetings,

Matthias

[rprosperi]

(02-01-2015 11:41 PM)matthiaspaul Wrote:  Not having opened a 20B or 30B so far, do they both use the same PCB? Would it be possible to sacrify a 30B for parts to be implanted into the case of a 20B?

Greetings,

Matthias

Good idea. I do like how the darker body looks, would make a nice 31S chassis.

[walter b]

(02-01-2015 11:46 PM)rprosperi Wrote:  

(02-01-2015 11:41 PM)matthiaspaul Wrote:  Not having opened a 20B or 30B so far, do they both use the same PCB? Would it be possible to sacrify a 30B for parts to be implanted into the case of a 20B?

Good idea. I do like how the darker body looks, would make a nice 31S chassis.

Heat stakes! Do I have to say more? Painting is easier IMHO.

d:-I

[rprosperi]

(02-02-2015 04:03 PM)walter b Wrote:  Heat stakes! Do I have to say more?

d:-I

Nope. That's enough for me, thanks Walter. If this was noted above, I missed that comment, sorry.

[MarkHaysHarris777]

(02-01-2015 02:52 PM)Dieter Wrote:  However, the 30B with its silver faceplate does not nearly look as nice as the all black 20B. Maybe that's why the emulator skin shows an all-black calculator as well. So I wonder if a 20B could be an option. The essential difference is the keyboard – the 30B keyboard is said to be much better. But how bad is the 20B in that regard? Would I sacrifice something substantial if I flashed the much nicer, all black 20B to become a 31s?

I have two comments, both of which are going to get me shot here:

1) The 20b keyboard uses silicone bubble dome technology (used on almost all modern computer keyboards today, and 99.9 % of all calculators on the market today) which is by far the superior technology for calculator keyboards, IMHO. The metal dome rock & click keyboards of the HP traditional line of calculators (loved by all true HP affectionados) are 'vastly' inferior key technology. They usually have a metallic dome (steel) and are nickel plated. They suffer from oxidation and contact bounce. The physical symptoms of which are missed keystrokes, multiple keystrokes/press, and dead keys before the life of the calculator/ they are difficult to clean, and once the metallic domes break, they cannot be repaired. Silicone bubble dome technology on the other hand is reliable, clean, and lasts virtually forever. They are easy to clean but rarely need to be (sometimes the copper unders need cleaning, but not usually because gold plating). So, no, the 20b keyboard is not all that bad... in fact, its pretty good actually.
1b) Having said that, I deliberately chose the 30b for its keyboard. I like the little clickers, the rocker action in the button is classic, and its just what I have come to expect from a true HP style calculator with class and pizzazz! ( I may repurpose a 20b just for fun, and for the collection... ) I am living with missed keystrokes and double keystrokes on my 34s. On my unit for instance, the 'h' green key will often not register. I noticed looking a little closer that it is actually registering 'twice'; going on, then off, very fast. Pressing the keys a little more firmly eliminates the problem mostly. But, silicone keys do not have this problem AT ALL.

2) The metallic face plate of the 30b is classy, and IMHO has the better curb appeal; just looks more professional to my eye, which has a clean fresh appeal and a sharper contrast / look. I agree with some other comments that photos do not do the 30b justice for looks/contrast. But hey, this is just personal preference. If you like the 20b, then go for it.


PS... if the metallic dome nickel plated keys could also be 'gold' plated over 'gold' contacts, and if the calculator implemented full contact debounce (more difficult and more expensive with single click keys) then ok... but think about it... the keyboard alone would cost $400.00 /

marcus

[Marcus von Cube]

(02-02-2015 06:03 PM)MarkHaysHarris777 Wrote:  I am living with missed keystrokes and double keystrokes on my 34s.

This bugs me! I've put considerable effort in the key debounce software and even with a bad keyboard bouncing should not happen at all. Your device must be really bad or my debounce algorithm isn't up to the task.

[MarkHaysHarris777]

(02-02-2015 06:49 PM)Marcus von Cube Wrote:  

(02-02-2015 06:03 PM)MarkHaysHarris777 Wrote:  I am living with missed keystrokes and double keystrokes on my 34s.

This bugs me! I've put considerable effort in the key debounce software and even with a bad keyboard bouncing should not happen at all. Your device must be really bad or my debounce algorithm isn't up to the task.

Marcus, don't panic yet... keep in mind, I'm running my 34s on a back-level version (till I mod with crystal and caps). When did you do your debouncing work? Does the unit need the crystal to make any of it work correctly? Also, I did not mean to make it sound like it was frequent... in using the unit yesterday for a couple of hours I saw the behavior twice (and I probably pressed the h green key hundreds of times).

marcus

[Marcus von Cube]

(02-02-2015 06:52 PM)MarkHaysHarris777 Wrote:  Marcus, don't panic yet... keep in mind, I'm running my 34s on a back-level version (till I mod with crystal and caps). When did you do your debouncing work? Does the unit need the crystal to make any of it work correctly?

The keyboard scan was the first part of the hardware port I put my hands on. It's interrupt based but doesn't need the crystal. The routine hasn't changed since 2011.

[BarryMead]

(02-02-2015 06:03 PM)MarkHaysHarris777 Wrote:  I am living with missed keystrokes and double keystrokes on my 34s

Eric Rechlin has noticed that a few of the HP-30B's that he modifies have bad keys. He tests every key on the calculator for reliable operation before he converts them into WP-34S calculators. One of the three that I converted has a problematic key. In my case it is the number "4" key that misses keystrokes on occasion.
The issue has something to do with bent over pressure nubs on the back side of the key. There are some articles about fixing the keys in older forum postings. Eric has a box of bad HP-30B's that he has accumulated over the years. In my case if you have one with a "GOOD" keyboard, it always performs perfectly.

[Shawn Gibson]

(02-02-2015 04:03 PM)walter b Wrote:  

(02-01-2015 11:46 PM)rprosperi Wrote:  Good idea. I do like how the darker body looks, would make a nice 31S chassis.

Heat stakes! Do I have to say more? Painting is easier IMHO.

d:-I

I've done the heat stake and paint thing. See this post:
http://www.hpmuseum.org/forum/thread-2161.html
Shawn

[MarkHaysHarris777]

(02-03-2015 01:21 AM)BarryMead Wrote:  

(02-02-2015 06:03 PM)MarkHaysHarris777 Wrote:  I am living with missed keystrokes and double keystrokes on my 34s

Eric Rechlin has noticed that a few of the HP-30B's that he modifies have bad keys. He tests every key on the calculator for reliable operation before he converts them into WP-34S calculators. One of the three that I converted has a problematic key. In my case it is the number "4" key that misses keystrokes on occasion.
The issue has something to do with bent over pressure nubs on the back side of the key. There are some articles about fixing the keys in older forum postings. Eric has a box of bad HP-30B's that he has accumulated over the years. In my case if you have one with a "GOOD" keyboard, it always performs perfectly.

Well, I repurposed my third 30b tonight (crystal & caps) with calc_xtal_full.bin on [34S 3.3T 3742] and have been putting it through its paces... noticing that the keyboard is clicking away flawlessly (could not ask for better). My son's unit is working well, or at least well enough that he hasn't complained about it. I wish that the team in China had opted to assemble the unit(s) with small screws, as in the 35s. If I thought I could pop all the plastic rivets on my unit with bad keyboard and somehow get it snapped back together with a solid-but-not-sticky keyboard I think i'd try it... on the other hand, its already broke, right? How much worse could I screw it up (ok, I'll give it a try tomorrow... er, I mean later today).

marcus