HP15CLE old can of worms

[Shawn Gibson]

Having just read the post comparing the HP15CLE and HP15C, I wonder speculatively about the possibility getting a fixed HP15CLE?

As I understand it:
1) The HP15CLE is running the same processor as the HP30B ( or at least the same ARM family).
2) The HP15CLE has the same connector for flashing as the HP30B.
3) The WP31 has been created from the FANTASTIC work done by the WP34 team.
4) HP is not likely to get us an update.
5) HP is not producing the HP15CLE any longer.

Now for what I do not know:
1) Is the schematic available?
2) Would remapping the LCD be worth the trouble?
3) Is there enough interest in the community to take on the project?
4) Is the original source code available for the 15C?

The project being, create a replacement flash image for the HP15CLE ( HP12...) that
is based on the WP34 work that could correct the issues that have been identified
in the HP15CLE so far.

Wishful thinking?
Shawn

[Katie Wasserman]

(07-07-2014 04:00 PM)Shawn Gibson Wrote:  Having just read the post comparing the HP15CLE and HP15C, I wonder speculatively about the possibility getting a fixed HP15CLE?

Now for what I do not know:
1) Is the schematic available?

It's just the ARM (same as the 30b) and the LCD, a slimmed down version of the 30b PCB for which the schematic is available in the SDK.

Quote:2) Would remapping the LCD be worth the trouble?

Mapping out the LCD and keyboard is pretty easy to do.

Quote:3) Is there enough interest in the community to take on the project?

I have no idea.

Quote:4) Is the original source code available for the 15C?

The project being, create a replacement flash image for the HP15CLE ( HP12...) that
is based on the WP34 work that could correct the issues that have been identified
in the HP15CLE so far.

If the source code were available we (I for one) would have fixed the 15CLE bugs long ago. Another option would be a WP34-like project to re-create all the functionality of the 15C. While I'm sure some of the WP34 code could be re-used it would still be a big project. A third option is to use an emulator running on the ARM and the original 15C binary image, like Swiss Micros did for their line of mini-voyagers. The 15C binary image is floating around out there but I think that there are copywrite issues with that. (Maybe not since Swiss Micros seems to get away with it.)

Quote:Wishful thinking?

Probably

[walter b]

I addition to what Katie said already: Why should anybody of the community be interested in re-creating anything on that 15CLE (12C) platform?

• We've got the WP 34S which can do anything the 15CLE can do but better IMHO.
• The 15CLE features an even less versatile display than the 30b. (Hardly possible but yes, they made it )
• For everybody wishing a very clean UI we offer the WP 31S.
  

So, really, who needs a 15CLE? Of course, YMMV.

d:-)

BTW, thanks for your kind words about the WP 34S.

[Thomas Radtke]

FWIW: Personally, I'm not interested in a reimplementation as I do not intend being a beta tester. I bought the 15C LE *because* it was supposed to work exactly like the 15C. Unfortunately, only HP (or a licensee) may distribute a corrected firmware containing the original ROM. And here the story ends for me.

[d b]

A couple of years ago either Pauli or Marcus responded to the same question from me saying basically what Katie said. He added Walter's point that the screen is less versatile and it wasn't worth their time when they had the 20/30b to work with. That could all change if hp were to cancel the 20/30 before the 43 platform is ready from Eric & Richard. People get bored.

Still; I wish that someone would. Katie could do it before breakfast. If the writer were to not care about an exact emulation it could have a truly (and uselessly) large memory too.

If I remember correctly; the new 12c is the same as the 15cle. If someone was to repurpose them, there would be a large and available source of units to re-do and Eric R could make a fine overlay.

But do I think it'll ever get done? Nope. And I wouldn't want work on the hypothetical improved 15 to make me wait one extra day for my 43.

[walter b]

(07-07-2014 07:08 PM)Den Belillo (Martinez Ca.) Wrote:  I wouldn't want work on the hypothetical improved 15 to make me wait one extra day for my 43.

Don't be afraid: neither Pauli nor me will waste a minute on the 12C/15CLE platform as is. And I'm pretty sure Marcus won't do either.

d:-)

[Thomas Klemm]

(07-07-2014 04:42 PM)walter b Wrote:  

• We've got the WP 34S which can do anything the 15CLE can do but better
  

A few things where I still prefer the HP-15C:

• Complex mode instead of having to perpetually use the CPX key.
• Intuitive way to handle matrices instead of having to remember matrix descriptors.
• Simple way to enter the elements of a matrix instead of using a program MED that isn't part of the MATRIX menu. Why is it missing?
• Support of complex matrices.
• LOG key instead of LG.
• Consistent use of order of stack elements for functions with more than one argument instead of using both for no apparent reason.
• No menus.
• Clean keyboard design instead of overloaded clutter.
  

Cheers
Thomas

[Katie Wasserman]

(07-07-2014 10:25 PM)Thomas Klemm Wrote:  

(07-07-2014 04:42 PM)walter b Wrote:  

• We've got the WP 34S which can do anything the 15CLE can do but better
  

A few things where I still prefer the HP-15C:

Let me add some to your list:

• a nicer form factor than the 20b/30b, IMHO
• better LCD contrast, better key clicks (this seems to vary a lot though)
• no need for a template and key stickers
• zero learning curve, a lot of people know the 15c backwards and forwards
  

[lrdheat]

My 15C LE enters multiple 3's often when I intend to enter a 3. The fatal failure is that suddenly, the 6 key stopped working.

When the 15C LE worked, I liked how quickly integrations converged on a result compared to the 34S. I found myself wishing, however, that it could handle x-root-of y when encountering problems dealing with odd roots of a negative number.

[Les Bell]

(07-07-2014 04:49 PM)Thomas Radtke Wrote:  FWIW: Personally, I'm not interested in a reimplementation as I do not intend being a beta tester. I bought the 15C LE *because* it was supposed to work exactly like the 15C.

I feel exactly the same way. The 15C has become something of a legend and often discussed here; I bought a 15C LE just so I could pick one up to see what people were discussing. It certainly isn't my "daily driver" - that job falls to my 41's - but it was an interesting addition to the collection. And a 15C LE with completely different firmware - even if it could be done - well, it wouldn't be a 15C any more.

[walter b]

(07-08-2014 12:43 AM)Katie Wasserman Wrote:  

(07-07-2014 10:25 PM)Thomas Klemm Wrote:  A few things where I still prefer the HP-15C:

Let me add some to your list:

So we're looking forward to your TK-15C

d;-)

[Katie Wasserman]

(07-08-2014 03:02 AM)Les Bell Wrote:  And a 15C LE with completely different firmware - even if it could be done - well, it wouldn't be a 15C any more.

I think that we're all (mostly?) in agreement that what we want is bug-fixed 15C LE nothing more than that. Without HP fixing this or making the source code available it would be a big project that would have different firmware but ideally would exactly duplicate the 15c functionality.

[Shawn Gibson]

Thank you all for your replies. I too purchased a 15cle just to see what all of the hubbub was about. I think it is a handsome calc, but I tend to use either my HP20S or my WP34s for most chores. It seemed that a fix might be within our grasp. I do understand the reluctance to pursue it any further though. Hey HP, any chance that that the source code could be made available for a patch? Yea, wishful thinking.
Shawn

[walter b]

IIRC there's a forum member who once had that source code - at least he was able to offer some nonpareil Voyager emulators/simulators (I never remember which's which). Then, shortly (some months) before the HP-15CLE appeared, that offer vanished. I think it must be within your reach now to find out that person by searching the archives.

HTH a bit.

d:-)

[robert rozee]

there is a much much easier approach to fixing the 15C.LE bugs, that involves precisely no programming and no circuit design:

purchase a modern 12C (that has the same mechanics as the 15C.LE). strip out the internals and from the mechanical dimensions create a PCB that fits within the casing, with the circuitry for the swiss micros clone laid out on the board. program the processor with the swiss micros 15C code - which i believe is freely downloadable. i strongly suspect the swiss micros guys would even be willing to lend you a hand in the form of email support of your endeavours.

at this point you can either:

1. relabel the 12C keys and escutcheon as required using the methods used to create the WP-34, then reassemble your newly created PCB into the re-purposed 12C case, or,

2. strip out the internals of your rather expensive 15C.LE and refit your new PCB into that casing. the finished product will be indistinguishable from the 15C.LE but lack all of the bugs. it will also likely enjoy a considerably extended service life to that of an original 15C.LE.


rob :-)

[Thomas Radtke]

OT & BTW Swiss micros ... a nice addition to the emulator would be a module to translate key codes to mnemonics. Shouldn't be too difficult to identify program mode and keycode by analysing the LCD signals.

[Nick_S]

This would be a nice project -- to complete a final firmware for posterity. Could it be done by patching the current firmware? There are a large number of HP-15C Limited Edition calculators out there and they offer speed improvements over the original as well as being very robust. I am still on my first sample which has accidentally done the floor drop test a number of times, with other samples bought as back-ups remaining in their boxes in storage. It is the right-level of size, functionality and clear design such that I never need to use the manual to check how to do something I have in mind.

Nick

[Thomas Radtke]

(07-16-2014 05:00 PM)Nick_S Wrote:  Could it be done by patching the current firmware?

Even if one is willing to disassemble the emulator firmware (we won't get the sources), there's no known way to get the machine code out of the 15C LE. And of course, a new LCD capable to display this mnemonics would be in order.