Re: Voyager 1xC emulation in the same unit?

[uhmgawa]

Exhuming this month old thread for context..

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Message #15 Posted by uhmgawa on 22 Dec 2011, 5:24 p.m.,

Porting KEMU to the HP-12C+ or 15c le is relatively straightforward. But I'd be more interested to do so as part of a larger functional upgrade...

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in response to message #15 by uhmgawa

That is a laudible goal which would be greatly appreciated, but I'm sure a lot of people would be very, very happy with a straightforward port, if you should ever be so inclined.

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What I had in mind was something like this, described in the latter part of
the video.

A KEMU port to a stock sam7 voyager isn't much of a technical
hurdle. Rather the question of native firmware status is more
of an issue, particularly for a multi-personality voyager.

[Bart (UK)]

Nice idea, however having multiple types on one unit presents problems with the keyboard. For functions not directly on the keys, an overlay would be fine of course, but how to change what's on the keys in an instant?

I think it might be a better idea to buy multiple 15C LE units and re-program dedicated units and have overlays like for the WP-34s.

There would of course be copyright issues, even if the code was not a copy of the HP ROM but entirely re-written, it would be a "copy-cat" issue - but HP would have the benefit of extra hardware sales.

[uhmgawa]

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Nice idea, however having multiple types on one unit presents problems with the keyboard.

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Indeed it does. The multi-firmware aspect was interesting
(at least to me) from an experimental perspective. But the
issue of key legends varying between models is a limitation,
arguably offset by the partial solution of key legend support
possible with a graphic display.

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For functions not directly on the keys, an overlay would be fine of course, but how to change what's on the keys in an instant?

I think it might be a better idea to buy multiple 15C LE units and re-program dedicated units and have overlays like for the WP-34s.

There would of course be copyright issues, even if the code was not a copy of the HP ROM but entirely re-written, it would be a "copy-cat" issue.

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Before going through that effort, there is the more fundamental
missing feature of interoperation (minimally data exchange)
between models. Adding it is certainly possible. However
the time is far more productively applied to creating
maintainable and extensible firmware -- an approach which can
straightforwardly address not some, but all of the above.

[Jeff O.]

I can see that what you would like to do would be an improvement over a simple port to a sam7 voyager if the hardware were available. I would of course encourage the simple port, because the hardware is available (in my hands, even.) But with the concern over the legality of using the original rom images or reproducing their functionality, I could not blame you if you did neither.

[uhmgawa]

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I can see that what you would like to do would be an improvement over a simple port to a sam7 voyager if the hardware were available.

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I believe I'd started down this slippery slope with a well
intentioned push from WalterB [appreciated] in the course of
discussing my KINOMI/NUT replacement project. Yet even if
one could scare up a display retrofit, there are interconnect
issues to resolve. And quite honestly the easiest way to
address this is with a new board layout which is a relatively
simple task. Well if we've got a new board layout it is
difficult to resist adding the sorely missing functionality in
that otherwise vacant PCB real estate. But wait, if we're
creating a replacement board there really isn't any compelling
reason to put an aged AT91SAM7L128 back into the design -- we
could do considerably better with a more recent SoC. And
having arrived at the foot of the slope, what are we really
repurposing besides an ABS enclosure in a unique form factor?
If we toss out that design constraint we no longer have the
severe display retrofit limitation.

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I would of course encourage the simple port, because the hardware is available (in my hands, even.)

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Admittedly a valid argument exists there as the hardware is
quite underutilized. Only about 25% of that 128KB flash is
actually needed to contain the 15c legacy firmware and a
NUT/Voyager emulator. Even the graphic voyager prototype
depicted above with KEMU core, all of 11/12/15/16c rom images,
multiple firmware support, serial console, graphic rendering,
several fonts, demo cruft, etc.. doesn't even cross over 64KB
on a C language challenged architecture. Add to this the idle
resources present in the
sam7 voyager
and it is difficult to resist improving upon the design.

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But with the concern over the legality of using the original rom images or reproducing their functionality, I could not blame you if you did neither.

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Well, there is certainly precedence for releasing an emulator
decoupled from its essential firmware. Yet doing so makes for
somewhat of a poorly scaling proposition where each user needs
to locate and program firmware images before a unit is functional.