DM42

[Pekis]

Hello,

Will there be a DM42 app ?

Obviously, it cannot be Free42 ...

[Thomas Okken]

(01-07-2018 06:25 PM)Pekis Wrote:  Will there be a DM42 app ?

You could ask SwissMicros when they're planning to release the DM42 source code -- that would be a big step toward that goal.

(I'm not interested in building a DM42 app myself, but it should be possible for others to do so, if they wish. The DM42 firmware is based on Free42, and since Free42 is GPL-licensed, SwissMicros must make their version of the code available to anyone who purchases a DM42.)

[pier4r]

what would be the difference between DM42 and free42?

[BarryMead]

(01-07-2018 08:54 PM)pier4r Wrote:  what would be the difference between DM42 and free42?

I don't yet own a DM-42, so this is only a guess. But I would imagine that the differences between the two would be tiny as the DM-42 is running free42dec under the hood. The differences will be in dealing with display contrast, self test operations, and the USB connection that is about all.

[pier4r]

but an android app (or win/mac) does not need that. I mean: contrast, self test, usb. Or maybe usb to control the real thing.

[Thomas Okken]

(01-07-2018 08:54 PM)pier4r Wrote:  what would be the difference between DM42 and free42?

The DM42 has a larger screen, and it uses the extra space to show more program lines at one (up to eight, I think), or show all four stack levels plus LASTx or ALPHA. You can choose between two fonts, each at several sizes. You can also control all those pixels using PIXEL and AGRAPH. It's really nice and well executed.

[Michael de Estrada]

The DM42 also has many additional functions, including time and date control and display. You can even determine the day of the week from the date using the DOW function.

[salvomic]

(01-07-2018 09:56 PM)Michael de Estrada Wrote:  The DM42 also has many additional functions, including time and date control and display. You can even determine the day of the week from the date using the DOW function.

as in Free42 (and 41CX), but not in 42s...

I don't know if Swiss Micros would like to make a DM42 app, if yes I hope to have Free42 and that app together in my iOS

[grsbanks]

I believe there are plans to release an SDK but this is some time in the future. I don't know what the scope of that SDK will be or what hardware platforms will be supported. Presumably it will allow an app to be developed for the supported platform(s) but I couldn't tell you when this will happen, whether it actually will happen at all or what platform(s) would be supported. Not because I'm bound not to tell but because I don't know.

[Michael de Estrada]

(01-07-2018 10:09 PM)salvomic Wrote:  

(01-07-2018 09:56 PM)Michael de Estrada Wrote:  The DM42 also has many additional functions, including time and date control and display. You can even determine the day of the week from the date using the DOW function.

as in Free42 (and 41CX), but not in 42s...

I don't know if Swiss Micros would like to make a DM42 app, if yes I hope to have Free42 and that app together in my iOS

I don’t have Free42 or an HP 41CX, so I was not aware of that. As to emulators in general, I prefer the physical real thing, although I do have the HP 15C on my iPhone.

[salvomic]

(01-07-2018 10:24 PM)Michael de Estrada Wrote:  I don’t have Free42 or an HP 41CX, so I was not aware of that. As to emulators in general, I prefer the physical real thing, although I do have the HP 15C on my iPhone.

I agree, but I'm using also emulators (especially HP 15C, yes), as they are always with me in the phone (or iPad) also when I cannot bring a calculator...

It's a pity that HP 42s hasn't date, time and dow function, that where in 41CX and are now in DM42, but that the same a good calculator, one of the preferred for me.

Salvo

[Dave Britten]

There's a Free42 fork for iPhone called "42S", by Byron Foster, which has some enhancements like a bigger display, and an RPL-like infinite stack. While it still works, and is currently available in the App Store, it's gotten minimal updates over the years, and is kind of a rough fit on more recent versions of iOS.

[emece67]

(01-07-2018 07:19 PM)Thomas Okken Wrote:  The DM42 firmware is based on Free42, and since Free42 is GPL-licensed, SwissMicros must make their version of the code available to anyone who purchases a DM42.

They must make available all the code inside the DM42 or only the code derived from Free42?

Regards.

[Thomas Okken]

(01-08-2018 12:52 PM)emece67 Wrote:  

(01-07-2018 07:19 PM)Thomas Okken Wrote:  The DM42 firmware is based on Free42, and since Free42 is GPL-licensed, SwissMicros must make their version of the code available to anyone who purchases a DM42.

They must make available all the code inside the DM42 or only the code derived from Free42?

That's a tricky question to answer, but I think the consensus is that the GPL covers the entire executable, but not anything outside the executable.

So, it covers the changes made to Free42 that support the big screen, but the parts of that big-screen drawing that take place not in the Free42 process but in the OS (in other words, the DM42 equivalent of the Windows Graphic Device Interface, GTK, MacOS Quartz, etc.) could be proprietary, closed source.

That is a bit of an over-simplification, though. I know there have been long and tricky discussions over this issue regarding the separation between the Linux kernel and kernel modules, for instance. Simply moving code to a dynamically-linked library does not necessarily make it "not part of the code." The full text of the GPL is long in part because capturing the desired ethos in legalese is hard.

[matthiaspaul]

(01-07-2018 07:19 PM)Thomas Okken Wrote:  The DM42 firmware is based on Free42, and since Free42 is GPL-licensed, SwissMicros must make their version of the code available to anyone who purchases a DM42.

Since the GPL is discussed right now, I'd like to remark that SwissMicros must make their source code (to the extent applicable) available not only to anyone who purchased a DM42, but to anyone else as well on request (including non-customers). And they are bound to license it under the GPL (in addition to this, they could dual-license their new code snippets under other licenses as well - just as well as you as the copyright owner of Free42 would be free to offer a more permissive dual-license to them for the parts you wrote).

Greetings,

Matthias

[Thomas Okken]

(01-08-2018 03:42 PM)matthiaspaul Wrote:  

(01-07-2018 07:19 PM)Thomas Okken Wrote:  The DM42 firmware is based on Free42, and since Free42 is GPL-licensed, SwissMicros must make their version of the code available to anyone who purchases a DM42.

Since the GPL is discussed right now, I'd like to remark that SwissMicros must make their source code (to the extent applicable) available not only to anyone who purchased a DM42, but to anyone else at well on request (including non-customers).

Not true. Link: DoesTheGPLRequireAvailabilityToPublic

EDIT: That's not exactly the link I was looking for. This one covers the DM42 source code situation: GPLRequireSourcePostedPublic.

[matthiaspaul]

(01-08-2018 05:55 PM)Thomas Okken Wrote:  Not true. Link: DoesTheGPLRequireAvailabilityToPublic

EDIT: That's not exactly the link I was looking for.

Yep, that's about the distributors' right to charge a fee for source code distribution if they want to. They can charge a fee for the distribution or the media, and cannot be forced to provide this service also to non-customers. Quite reasonable, but a different scenario.

Quote:This one covers the DM42 source code situation: GPLRequireSourcePostedPublic.

gnu.org Wrote:The GPL does not require you to release your modified version, or any part of it. You are free to make modifications and use them privately, without ever releasing them. This applies to organizations (including companies), too; an organization can make a modified version and use it internally without ever releasing it outside the organization.

No surprises so far.

However, the following interpretation offered on gnu.org is quite interesting as it partially undermines what, in my understanding, is (or was?) part of the "virual" spirit of the GPL (boldface by me):

gnu.org Wrote:But if you release the modified version to the public in some way, the GPL requires you to make the modified source code available to the program's users, under the GPL.

I was living under the impression that anyone can do with GPLed code what they want, including modifying it, but that the source code of the derivative work must be made available to anyone who wants it when the derivative work is published as well.

As the GPL does not allow the exclusion of any kind of military use, very few of my own projects were ever licensed under the GPL, that's why so far I only studied the GPL 2 more thoroughly. Perhaps the terms have changed in newer versions.

From the GPL 2 section 2 and 3 (boldface by me):

GPL2 Wrote:2. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you also meet all of these conditions:

a) [...]
b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.
c) [...]
[...]
3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following:

a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,
b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,
c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.)
[...]
If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code.

Greetings,

Matthias

[Thomas Okken]

The first time I realized this was when I talked to Markus Gonser about parasites putting up clones of existing GPL programs on the iTunes App Store (there are at least two, possibly three, such clones of Free42 for iOS, and I'm *not* referring to Byron Foster's 42s!). He told me that he had taken the m48 source code down from his web site, and was only giving it to people who installed his app. He acknowledged that this represented only a minor speed bump against parasites, since once someone has the source, they can still redistribute it, and sell derived works (*), all they want, but he felt it was better than doing nothing.

In the same vein, SwissMicros are only obligated to make the DM42 source code available to their customers, BUT if one of those customers wants to redistribute that code, they are free to do so.

I think it makes sense. If I'm a small business selling a GPL-based product, making source code available to my paying customers represents a minor and predictable cost, but if I had to provide the code to absolutely everyone who asked me for it, that could cost significant amounts of money and time (can't do anything about the time part, even if you charge a fee for the code). It wouldn't be reasonable to force people to deal with that. The important thing is that they can't *restrict* what their *customers* can do with the code, including redistribution.

(*) Even if "derived" means "rename it, slap a new skin and icon on it and build it, otherwise completely unchanged"...