HP-25C Eumulator

[Sylvain Cote]

(10-28-2014 12:18 AM)Chris Chung Wrote:  I had 4 assembled units that I can ship immediately. So I will follow the order and ask Massimo, hp41cx (2) and Sylvian to furnish payment and PM / email the shipping address to me.

Hello Chris,
Payment has been sent.
Thank you very much.
Best regards,
Sylvain

2014-11-05 Edit
I have received the calculator today.
Very nice unit and with a customized greeting 8-)
Thank you!
Sylvain

[Massimo Gnerucci]

Unit was delivered in record time!

Thank you very much, Chris.

And a nice touch, I must admit...

   

[Chris Chung]

(11-04-2014 04:58 PM)Massimo Gnerucci Wrote:  And a nice touch, I must admit...

I was debating if I should enter "Max Gnerucci" for your long name. Anyway, you are able to change it.

The units makes a interesting little toy, but it can not take abuse though. If you have some good ways to insulate the back better, it will be more reliable. It could pick up wrong keys because of stray capacitance from your fingers.

[Massimo Gnerucci]

(11-05-2014 08:57 PM)Chris Chung Wrote:  

(11-04-2014 04:58 PM)Massimo Gnerucci Wrote:  And a nice touch, I must admit... ;)

I was debating if I should enter "Max Gnerucci" for your long name. Anyway, you are able to change it.

As my avatar testifies... ;)

[Mark Hardman]

My NP-25C arrived in perfect condition yesterday. I immediately entered the Moon Landing Simulator--which ran without issue. I had not realized how small this marvel is. It is slightly narrower than a credit card. The keys have very good tactile feedback with a nice accurate snap to them.

I was thinking of creating some sort of overlay for the three emulated models. But, the keyboard is small. I strongly feel that the pure minimalist design should not be touched. Besides, after a few minutes of use, the old keystrokes lodged in the deep structures of my brain take over and I don't even need to look at the keyboard.

Here's a picture of the NP-25C with its three bigger siblings:

   

Chris, this is an amazing little creation. I would encourage you to pursue its commercial potential: Either as a miniaturized version of the original collectibles (similar to the SwissMicros DM versions of the Voyagers); or as a processor replacement for the large number of damaged ACTs inside Coconuts.

[SlideRule]

(10-24-2014 02:58 PM)SlideRule Wrote:  

(10-20-2014 12:39 PM)Chris Chung Wrote:  Yes, there is one remaining PCB and I've order more led modules. Please indicate if you want a kit or an assembled unit.

Assembled, please.

Chris
Received my unit yesterday in EXCELLENT condition (the extra padding on the on/off switch, parts etc.); inserted one CR2032 & viola!
three-in-one handy & portable woodstock-spice series emulators. KUDOS!
I'm looking into fabricating a case w/ covers. Hope for success. Thanks again for a marvelous project!
SlideRule

[Chris Chung]

Apologies to Neil again. I am still waiting for the additional buttons before I can mail your kit. After two weeks wait my supplier from HK sent me wrong buttons so it will take a bit more time. I did try to procure locally at higher cost but my local shop (newark.com) only carry black color buttons.

Also I over-charged the shipping. For Europe it's more like $8.00 and for US it's like $5.00, Canada $3. Before I was using small boxes (that I re-cycle from some on-line orders) and the shippings were pricer. Now I ship w/ padded envelops and they fits in a "light-packet" category (being thinner than 2cm) and thus cost less. I will just pocket the "tips" for other projects (say a HP-41) then .

If I have to ship again I will adjust the cost for you.

(11-14-2014 11:58 AM)SlideRule Wrote:  I'm looking into fabricating a case w/ covers. Hope for success. Thanks again for a marvelous project!

I was thinking of creating a very simple "sleeve" for it. I.e. kind of slide out, flip-over, slide back in type, like a modern TI-108. I want to show off the circuitry while in use but have some protection on the back. It would be a good project for a 3D print, except I don't have a 3D printer

really nice and simple calculator, scroll down on this link to see the case.

(11-13-2014 07:58 PM)Mark Hardman Wrote:  My NP-25C arrived in perfect condition yesterday. I immediately entered the Moon Landing Simulator--which ran without issue. I had not realized how small this marvel is. It is slightly narrower than a credit card. The keys have very good tactile feedback with a nice accurate snap to them.

Thanks for your excellent picture and mini review, it's good to see it along w/ the original calculators it tries to emulate.

(11-13-2014 07:58 PM)Mark Hardman Wrote:  I was thinking of creating some sort of overlay for the three emulated models. But, the keyboard is small. I strongly feel that the pure minimalist design should not be touched. Besides, after a few minutes of use, the old keystrokes lodged in the deep structures of my brain take over and I don't even need to look at the keyboard.

Plastic sheet overlays w/ cut-outs would be ideal, yet like you said, the unit is quite small and it will be difficult to do.

(11-13-2014 07:58 PM)Mark Hardman Wrote:  Chris, this is an amazing little creation. I would encourage you to pursue its commercial potential: Either as a miniaturized version of the original collectibles (similar to the SwissMicros DM versions of the Voyagers); or as a processor replacement for the large number of damaged ACTs inside Coconuts.

I guess such a product is possible in a hobbyist marketplace. I am actually planning to sell my other emulator (TI DataMath) on an electronic marketplace (tindie.com). The DataMath is easier to manage and I am more confident to offer it as a kit. At same size but w/ fewer buttons and only basic functions, it's a better "toy" than the NP-25. It's more finger friendly and the no-RPN nature is more comfortable to most. I have both units sitting on my desk and the "go-to" calculator is the DataMath.

For the NP-25, I am somehow reluctant to offer it as a kit at the moment, although I think I have the most simple design possible, it has one more chip and way more buttons and require components on both side of the PCB. I worry the kits would have less successful build rate. I would keep it as it is now and may be order another batch of 10 PCBs (w/ better silkscreen) for another round mini "group-buy" if there are more wants.

For a brain transplant design, a couple of members had asked for the h/w design, so hopefully we will see something in the future. If you have my PCB and an old unit, may be you can gauge-fit it and see what kind of approach is needed. LED brightness, PCB sizing, plan / sketch-up key placements. I am curious on whether the LEDs are the same size (so will be possible to use new LEDs). I am always happy to advised / help if someone take the lead.

I looked at the "DM"s and they are quite interesting. Except I would want to have the 7 segments back. I guess you will have to make a compromise as they are not common parts anywhere. I would really like to do a HP-41 and again the LCD is the biggest problem. Using a graphic module to "pretend" the 14 segments doesn't look right to me, but may be the only solution (except to shell out $1-2k for custom LCDs).

[Massimo Gnerucci]

(11-14-2014 02:01 PM)Chris Chung Wrote:  I would really like to do a HP-41

My hero!

[Guenter Schink]

Hi Chris

Whenever you plan to have another batch of the assembled HP-emulators, I'd like to get one of those.

Günter

[brouhaha]

(11-14-2014 02:01 PM)Chris Chung Wrote:  I would really like to do a HP-41

The -41 was originally the primary objective of the DIY series of calculators Richard Ottosen and I developed. Our first four models (DIY0 through DIY3) used PIC microcontrollers, with increasing amounts of memory. Like what you've done, we started with the Woodstock and Spice series. Our conclusion was that even the bigger, faster PIC18 part in the DIY3 wasn't fast enough to make a usable -41 without having to code most of the simulation code in tightly written and highly optimized assember, and even then the speed wouldn't have been great.

Quote: and again the LCD is the biggest problem.

Same with ours. We used a 16x2 character LCD module made by Lunex, and it only has 8 programmable characters, so it's not possible to replicate any possible use of the 41 display. The inter-character punctuation is also a problem.

It's hard to find ANY off-the-shelf display or display module that's the right width for a handheld calculator. Real commercially made calculators all use custom displays, and there's apparently very little market for a calculator-sized LCD as a standard product. It's easy to find LCDs that are either much smaller or much larger than desired for a calculator.

Quote:Using a graphic module to "pretend" the 14 segments doesn't look right to me, but may be the only solution (except to shell out $1-2k for custom LCDs).

I was perfectly willing to use a graphic display with a mostly "normal" bitmap font, rather than trying to replicate the -41 segmented display appearance.

We did find a bitmap graphic LCD module with the same outline dimensions as the Lumex 16x2 character module, but the contract is awful unless a backlight was used.

On the DIY4, we switched from PIC to Energy Micro Gecko, and later Giant Gecko, which use an ARM Cortex-M3 core. These provide more than enough CPU power for a -41, and that's the first thing I got running on them. The DIY4 originally used the Lumex 16x2 character display. We hacked a 2.7-inch diagonal graphic LCD onto it in place of the character module using an adapter board, which I refer to as the DIY4X and that was vastly superior, but quite expensive. The choice was made beacuse the 2.7" diagonal display was much taller than we wanted, but the width was exactly what we wanted. The price of that graphic LCD has come down somewhat since then. We redesigned the hardare to support the graphic display natively, as DIY5, and I've showed it at conferences in two versions, one running -41 simulation (hacked to optionally show all four stack levels), and one natively running Thomas Okken's Free42 (hacked for an 8-line text display). I polled the conference audience, and there was overwhelmingly more interest in running Free42 than the -41 simulation.

Richard and I are still planning to sell calculator hardware similar to the DIY5. It will be able to support several different open-source calculator programs, including Free42, WP-34S, and (eventually) WP-43S. The biggest challenge is that few people are willing to pay what we'll realistically have to sell it for, which is perhaps a bit less than $300. That's about the minimum we can sell it for and not lose our shirts just on the manufacturing cost; the pricing isn't an attempt to recoup any of the costs we've paid out of our own pockets for development, which I estimate to be over $10K so far, and probably at least another $20K to go, nor will it compensate us for any of our time spent, which even at minimum wage amounts to even more than the out-of-pocket expenses.

I certainly don't want to discourage anyone from working on such products, but as I've said before, making calculators is a great way to make a small fortune, only if you're starting from a large fortune. It's easy to build prototypes, and extremely difficult to build and sell a commercial-grade product that people will actually buy.

[pito]

(11-15-2014 07:17 AM)brouhaha Wrote:  [quote='Chris Chung' pid='21423' dateline='1415973670']
I would really like to do a HP-41

Quote:I certainly don't want to discourage anyone from working on such products, but as I've said before, making calculators is a great way to make a small fortune, only if you're starting from a large fortune. It's easy to build prototypes, and extremely difficult to build and sell a commercial-grade product that people will actually buy.

When observing today's population starring into their androidal gadgets, quite cheap and powerful today, then I doubt people will buy a calculator (except the enthusiasts and collectors). You may run almost everything on those nice smartphones today..

[Chris Chung]

(11-15-2014 07:17 AM)brouhaha Wrote:  The -41 was originally the primary objective of the DIY series of calculators Richard Ottosen and I developed. Our first four models (DIY0 through DIY3) used PIC microcontrollers, with increasing amounts of memory. Like what you've done, we started with the Woodstock and Spice series. Our conclusion was that even the bigger, faster PIC18 part in the DIY3 wasn't fast enough to make a usable -41 without having to code most of the simulation code in tightly written and highly optimized assember, and even then the speed wouldn't have been great.

Thanks for the heads-up. I am looking at the -41 code as a side project and already see that I need a different processor. Like the way I approach the woodstock, I try 1st to run your core emulation code (modified to platform) on a dev board initially via serial interface. Just to get a feel before designing the I/O aspects of the project.

Quote:...
It's hard to find ANY off-the-shelf display or display module that's the right width for a handheld calculator. Real commercially made calculators all use custom displays, and there's apparently very little market for a calculator-sized LCD as a standard product. It's easy to find LCDs that are either much smaller or much larger than desired for a calculator.
....
I was perfectly willing to use a graphic display with a mostly "normal" bitmap font, rather than trying to replicate the -41 segmented display appearance.

We did find a bitmap graphic LCD module with the same outline dimensions as the Lumex 16x2 character module, but the contract is awful unless a backlight was used.

As my project goal / audience is to create a retro computing toy piece, I really want to achieve as closely to the original look. So far no luck finding anything close.

Quote:On the DIY4, we switched from PIC to Energy Micro Gecko, and later Giant Gecko, which use an ARM Cortex-M3 core. These provide more than enough CPU power for a -41, and that's the first thing I got running on them. The DIY4 originally used the Lumex 16x2 character display. We hacked a 2.7-inch diagonal graphic LCD onto it in place of the character module using an adapter board, which I refer to as the DIY4X and that was vastly superior, but quite expensive. The choice was made beacuse the 2.7" diagonal display was much taller than we wanted, but the width was exactly what we wanted. The price of that graphic LCD has come down somewhat since then. We redesigned the hardare to support the graphic display natively, as DIY5, and I've showed it at conferences in two versions, one running -41 simulation (hacked to optionally show all four stack levels), and one natively running Thomas Okken's Free42 (hacked for an 8-line text display). I polled the conference audience, and there was overwhelmingly more interest in running Free42 than the -41 simulation.

I would think that an ARM core would be an overkill. The TI MSP430 family (being 16 bit) that I am using will offer something in between, and it offers very low power. I got particular interested in the -41 as I was playing w/ a new MCU (TI MSP430FRxx series) that has FRAM memory (data retention as continuous memory) and direct LCD segment driving. And I thought a LCD based calculator would make a nice project to showcase that particular processor.

Quote:Richard and I are still planning to sell calculator hardware similar to the DIY5. It will be able to support several different open-source calculator programs, including Free42, WP-34S, and (eventually) WP-43S. The biggest challenge is that few people are willing to pay what we'll realistically have to sell it for, which is perhaps a bit less than $300. That's about the minimum we can sell it for and not lose our shirts just on the manufacturing cost; the pricing isn't an attempt to recoup any of the costs we've paid out of our own pockets for development, which I estimate to be over $10K so far, and probably at least another $20K to go, nor will it compensate us for any of our time spent, which even at minimum wage amounts to even more than the out-of-pocket expenses.

Yes, I agree it is a limited market. With the need to move to SMD designs and graphic displays, the set-up cost will no doubt be a lot higher. I still has not made the jump due to the investments needed (microscope, re-flow station, etc). And it will not happen if you do not have passion on what you are doing.

Quote:I certainly don't want to discourage anyone from working on such products, but as I've said before, making calculators is a great way to make a small fortune, only if you're starting from a large fortune. It's easy to build prototypes, and extremely difficult to build and sell a commercial-grade product that people will actually buy.

I am in no way trying to make into a commercial-grade product. Just doing a group-buy had me worried (and understand) the quality process. The NP-25 units do not even have a proper case! I have not spend time to do power profiling, regression test, etc. It's really a DIY project and will remain as such. Actually the initial plan was to try create flashy badges (yet functional) for conferences, notice pcb w/ the slot for badge holders, like so



I am not sure how my pursue on the -41 will go. I would definitely try to make your code run on a 16-bit MCU since it's fun to do. But if I couldn't find a "pretty" LCD module the project probably will stop there.

(11-15-2014 12:28 PM)pito Wrote:  When observing today's population starring into their androidal gadgets, quite cheap and powerful today, then I doubt people will buy a calculator (except the enthusiasts and collectors). You may run almost everything on those nice smartphones today..

I agree. From a practical point of view, there are always apps. What I found from my calculator emulator projects, those curious on how things works would appreciate a physical unit over apps. I.e. enthusiasts and collectors. Another target audience group would be handmade crafts and vintage crowd, like as in etsy.com, where people looks for unique and one-of-a-kind items.

[BobVA]

(11-14-2014 02:01 PM)Chris Chung Wrote:  I would keep it as it is now and may be order another batch of 10 PCBs (w/ better silkscreen) for another round mini "group-buy" if there are more wants.

I'm in for one or two!

[EdS2]

(11-14-2014 02:01 PM)Chris Chung Wrote:  I would keep it as it is now and may be order another batch of 10 PCBs (w/ better silkscreen) for another round mini "group-buy" if there are more wants.

I'm in for one too Chris!

[Nigel (UK)]

I'd like one as well - assembled would be my preference, but a kit would be fine too.

Nigel (UK)

[Chris Chung]

Looks like we are set for another batch.

Guenter, BobVA, EdS2 (are you EdS from "retro computing circle"?), Nigel and another member had indicate interest.

I am going to fix the current PCB design's silk-screen and use a lower profile button (it will make the silkscreen more visible and the clicks will be lighter) for this batch of 10 units. It will take a few days for me to finish the PCB and another 3 weeks for fabrication. I hope it will be smooth on this design (this will be V3) and I can start to ship in 4/5 weeks. The cost again is CAN $30 for kit, $40 assembled. Shipping for each unit is $3.00 Canada, $5.00 US, $8.00 elsewhere.

I will be using the V0 screen silk (see below) and it resembles the HP-25 key legends (except those symbols I cannot reproduce).



I will keep you update on the progress.

[Didier Lachieze]

(11-18-2014 03:43 AM)Chris Chung Wrote:  Looks like we are set for another batch.

Guenter, BobVA, EdS2 (are you EdS from "retro computing circle"?), Nigel and another member had indicate interest.

Please count me in also. A kit would be fine for me.

[EdS2]

(11-18-2014 03:43 AM)Chris Chung Wrote:  (are you EdS from "retro computing circle"?)

That's me! Also known as BigEd over on 6502.org and at stardot.org.uk

[Chris Chung]

Guenter, BobVA, EdS2, Nigel, Mr.N, Didier

(11-18-2014 08:33 AM)Didier Lachieze Wrote:  Please count me in also. A kit would be fine for me.

The project is all thru-hole parts. But to conserve space, it's a double sized zigzag layout (like a back-split house) and will require cutting down some component pins during assembly. Also the tactile button spaces are rather tight and a thin tip temperature controlled iron will work better. Please watch my video (which includes construction) on the top post. You may decide to take a kit or assembled when we have the parts available.

(11-18-2014 09:00 AM)EdS2 Wrote:  That's me! Also known as BigEd over on 6502.org and at stardot.org.uk

Hi Ed, sorry I did not report the progress on "retro-computing". Not confident that it's 100% bug-free. So I had the project discuss here under HP experts' eyes. I will post it and a write-up on my project pages after this design version change.

[EdS2]

(11-18-2014 12:43 PM)Chris Chung Wrote:  ... I had the project discuss here under HP experts' eyes.

Good idea! A better place for a technical discussion anyway.