Never make a dime of profit...



#11

It is quite shocking that recent HP calculators have so many bugs. Are all current HP calculators this buggy? If I wanted to use a new HP calculator for serious work, which model should I get to have a minimum amount of bugs and problems? Did the older ones, like the HP-25, HP-65, HP-67 also have this many bugs? Do TI calculators like the TI-84 and TI-89 also have (many) bugs? It is really not something you would expect from a company like Hewlett-Packard. Remember Dave Packards wise words about the bugs in the HP-35: "We're going to tell everyone and offer them a replacement. It would be better to never make a dime of profit than to have a product out there with a problem"


#12

The HP-25, HP-65, and HP-67 you mention have very few known bugs, although there were some bugs in the HP-67 early on, and not all units in the field were upgraded to fix them. The same is true of the HP-41C; the HP-41CV and HP-41CX have all of the most serious bugs fixed.

The newer calculators definitely have a lot more bugs than the older ones, but they also have a lot more features, and thus contain a lot more code. I think it is to be expected that software with more features and more code will have more bugs.


#13

In my admittedly limited programming experience, the number of bugs in any piece of software rises at least in proportion to the increased complexity of any code written.


#14

Quote:
In my admittedly limited programming experience, the number of bugs in any piece of software rises at least in proportion to the increased complexity of any code written.

It may be that this is often the case, but it should not be like that. More code just means that it has to be tested and debugged better. From a company like HP, which supposedly delivers high quality equipment, that would be expected. Furthermore, some bugs are not related to the complexity. They even managed to create new bugs in old software, like the PSE bug in the 15c LE that is running the original 15c software, where this bug is not present. Remaining question: which currently available HP calculator has the least amount of bugs? The 50g perhaps?

Edited: 4 Jan 2012, 8:58 a.m.


#15

Don't underestimate the complexity of emulation. Especially the LCD controller in the original 15C seems to be hard to emulate correctly. The PSE bug is a consequence of an unsuccessful optimization attempt in this area.


#16

Quote:
Don't underestimate the complexity of emulation. Especially the LCD controller in the original 15C seems to be hard to emulate correctly. The PSE bug is a consequence of an unsuccessful optimization attempt in this area.

I would rephrase that and say the PSE bug is a consequence of not properly testing an optimization attempt. Those who had tested the calculator the previous year did not have that version of software. I have not seen any group come forward and claim they tested the released version of software. Unless you count those who purchased it.


#17

Firmware version 2011-04-15, which is the version loaded on the production machines, was made available on 2011-4-21 to some of those who tested the calculator the previous year. Unfortunately, apparently no one ran any tests using the PSE instruction, and no other issues with flashing displays or other odd behavior were reported. The memory corruption with self test problem had been found and reported with the previous firmware version. Unfortunately, the 2011-04-15 firmware was not re-checked for this problem. To my knowledge, power consumption was not measured by any user and power management was never considered or discussed.

#18

It is not hard to emulate the Voyager LCD controller correctly. It isn't a complicated device. I got it working correctly in only a few hours. I've even told the appropriate people how to do it, multiple times.

It's fine to optimize things, but it shouldn't be that difficult to verify that the optimization actually works correctly.

#19

Quote:
Don't underestimate the complexity of emulation. Especially the LCD controller in the original 15C seems to be hard to emulate correctly. The PSE bug is a consequence of an unsuccessful optimization attempt in this area.

The only area I've found where the voyager lcd controller model
itself can impact emulation is the lack of an inherent "update
logically complete" operation to aid synchronization. The
firmware simply writes to the display registers and the
controller captures these accesses, updating the lcd scan data
on the fly as a hardware function. Moreover as the voyager
firmware emits redundant display register updates, considerable
emulation time can be consumed to no benefit if the attempt is
made to render the emulated display on every register
modification. IOW if the cost of a display update is
substantial relative to the intended speed of instruction
emulation, this likely needs to be addressed.

The sam7's segment controller timing window constraints when
entering/exiting hardware blink mode probably aren't helping
here requiring the emulator update of the display effectively
to synchronize with the controller's internal timebase.
Add to this the practical need of the NUT instruction-to-glass
update to occur within a latency appearing acceptably responsive
to the user and overall there are some details which need to be
worked out specific to the sam7.

IIRC when first implementing graphic support for KEMU,
I'd reinitialized the phase of the blink
timebase with each 030 blink operation on the assumption doing
so would avoid runt blink periods. However exactly the opposite
was true as the firmware effectively disables and reenables
display blink mode for short intervals of time undetectable
to the user when blink phase is maintained. Of course in
hindsight that's exactly the behavior resulting from the
r2d2 controller's internal asynchronous, free-running timebase.

#20

Quote:
It may be that this is often the case, but it should not be like that...From a company like HP, which supposedly delivers high quality equipment, that would be expected.

Well, let's get a little perspective.

Here's some of the more important HP calculators produced since 1972, with their equivalent cost in 2011 US dollars (from US BLS)).

Model   Date  List Price   2011 Equivalent
HP-35 1972 $395 $2138
HP-45 1974 $395 $2012
HP-21 1975 $125 $ 526
HP-25 1975 $195 $ 820
HP-67 1976 $450 $1680
HP-41C 1979 $295 $ 919
HP-34C 1979 $150 $ 467
HP-15C 1982 $135 $ 316
HP-42S 1988 $120 $ 229

All these represent some top-quality popular HP calculators from "the good old days". The only one that would be a bargain at its inflation-adjusted price is the HP-42S.

If today it was possible to sell a perfect HP-15C for $316, I have no doubt that HP could match the original. But there would be few purchasers at that price. Frankly, everything available today is dirt cheap...an HP 50G is $150 list from HP, but typically $105 elsewhere. When the toys we buy are so cheap, there can be no logic attached to extensive error-checking and quality control prior to marketing. There ain't no such thing as a free lunch!

In addition, HP is usually awarded too much credit for perfection from 35 years ago. The Woodstock series have the most negligently- and incompetently-designed battery charging system in the history of portable calculators...it could and did easily destroy the calculator. A major product defect! The new HP-67 that I bought in 1977 (for a whole month's take-home pay) had some trigonometric result issues that HP addressed only by inserting a notice card with the manual. We've seen recently that the HP-15C has a basic bug with GSB and indirection that it handled, with NO notice made, by quietly eliminating the manual's reference to the intended function. The magnetic card readers on all HP calculators turn gummy. The battery door designs on most HP calculators really are weak, except for the ill-fated Woodstock line. The whole battery compartment design of the Clamshells is a horror which results in permanent cracking of the calculator case near the cell opening. I'm sure there are many more examples from the good old days of HP calculator history. On the cases I cite above, one could pay a lot of money for an item that was orders of magnitude less capable than today's models, and still wind up with a defective unit.


#21

While you're at it, why not mention the awful flimsy junk that were known as Spices ? Of all the calculators that HP ever produced, these had to be the worst in this respect, and even the cheapest HP calculator made today is much better.


#22

Quote:
While you're at it, why not mention the awful flimsy junk that were known as Spices?

Agreed! My list from the good old days is far far from complete. :-)

I like a lot of things about how the HP-34C functions, and the later soldered-chip version is passable. But even that feels flimsy, and the Spice battery door design was done by fools, apparently.

The successor, the HP-15C, has a few oddities of construction especially in the early models. The several iterations of later single PCB design were a great improvement, yet it's hard to understand why HP would make such drastic physical modifications without also correcting the GSB indirection bug that they didn't tell anyone about (but obviously knew about).


#23

RE: GSB, was that the one that someone reported here just discovering recently?


#24

Yes. Unknown to the customer community apparently, but well known to HP, 30 years ago. HP then "solved" the problem by eliminating from the manual the description of the GSB function that did not work (negative numbers in the I register), even though the feature works on the HP-11C. Cheesy and somewhat dishonest. Dishonorable!

#25

Quote:
If today it was possible to sell a perfect HP-15C for $316, I have no doubt that HP could match the original. But there would be few purchasers at that price.

I doubt that. I think they easily could have sold the first batch at $ 295 or more. There was and still is very high demand, and even higher prices were paid on eBay.

Quote:
When the toys we buy are so cheap, there can be no logic attached to extensive error-checking and quality control prior to marketing. There ain't no such thing as a free lunch!

From Hewlett Packard I do not expect cheap toys. If I want cheap toys there are lots of other manufacturers to choose from. From Hewlett Packard I expect high quality, well tested products. Of course at a higher price. Now it seems that we have no choice anymore: you can only buy cheap toys, even from Hewlett Packard.


#26

Only a handful of buyers, mostly outside the USA paid very high prices for the 15C LE. Go to ebaby now and you'll see dozens of listings for it at much lower prices that are not selling. I certainly would not pay that much for it, when I can buy a very clean original for the same price.

#27

Times are changing, and I suppose that the market for high-quality calculators is quite small. Calculators don't play the same role anymore, and the quality level of HP products is in the range of its competitors. The days of outstanding quality of HP products is gone.


#28

I'm dreaming if Agilent technolgy would make 42SII as an accessory of their measurement equipments line.

Lyuka

#29

Quote:
If I want cheap toys there are lots of other manufacturers to choose from.

The real problem is "who do you go to if you want quality that is better than what the idolized HP now provides?" I don't see any corporations eager to fill this "gap".

Contrary to what has been gratuitously asserted, there is NO verified (or likely) market of sufficient size that would pay $300 for an HP-15C. There's only a few oddballs with, arguably, a lot more money than sense. A company would be insane to go to the effort and expense to produce a Voyager or other old device that was identical or better in quality and performance to the 30 year old originals. Plus, as we know well, there were many surprising and significant lapses of quality of design and construction in many of the esteemed HP products of yesteryear.

One must resist the urge to live in a dream world that doesn't exist now, and in fact has never existed. I doubt that the entire HP calculator operation contributes significantly to HP's annual return to stockholders. Were I their CEO (apparently not much talent is required), I'd drop it altogether or sell it off if some imprudent buyer could be found.

#30

I agree with you in principle, however the following statement may require some further considerations:

"When the toys we buy are so cheap, there can be no logic attached to extensive error-checking and quality control prior to marketing. There ain't no such thing as a free lunch!"

I think market size, scale have to be considered here and would run counter to your hypothesis. In other words, take the preproduction market size estimate for the HP45, or the 657 etc, and compare it to the 15c or 42s market estimate. I think the market size grew much much larger with each generation and HP knew this and figured this into the price. The R&D was amortized over more units."

If we knew the estimated market size for the current production, we might find that in fact your hypothesis stand up: perhaps the latest production was based on a considerably smaller market, while still offering a lower price. "Something's gotta give" would apply here, in support of your hypothesis.


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