hp12C capability

[Todd Israels]

Will the new 12c with arm processor take the firmware for the 15C LE?
I do like the desighn of the 10 series calculators. Does the 12C+ have enough memory space to make it possible to have a 12C, 15C and 16C rom on board, so the calculator to run would be selectable? I know this would prove more complicated than it appears!

[Jeff O.]

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Will the new 12c with arm processor take the firmware for the 15C LE?

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Yes. The hardware is identical.

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Does the 12C+ have enough memory space to make it possible to have a 12C, 15C and 16C rom on board...

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Is 128 kB enough?

[uhmgawa]

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Is 128 kB enough?

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For an AVR target a KEMU config including 11c/12c/15c/16c support
weighs in at:

/usr/bin/avr-size kemu_m1284p.elf

   text	   data	    bss	    dec	    hex	filename

  51498	    162	   2239	  53899	   d28b	kemu_m1284p.elf

Note this in on a modest 8-bit AVR core which isn't exactly
the runtime architecture Dennis Ritchie had in mind. So I'd
expect ARM thumb code to do considerably better. Note however
the firmware occupies the lion's share of flash, thus any
reduction due to use of a sane runtime architecture will be
proportional to actual emulator code.

Even a 64KB sam7l would suffice if the above assumption holds.
Interestingly 24-28KB of flash is more than sufficient for a
single 15c configuration, and a 12c flash footprint would
further reduce that by 7.5KB. I'd expect quite a bit of elbow
room could be found in the sam7l128 used in the encore 12c/15c.

RWM (bss + data above) however would need to be partitioned
between the 2KB of battery backed and 4KB volatile regions.
But I think that is doable. Other features such as a CLI
interface and support (mapping the segment display to ascii,
etc..) are included in the above image, the RWM storage
for which doesn't need to be persistent over power off
periods or can be deconfigured altogether.

[Neil Hamilton (Ottawa)]

I am going to take a wild guess and say that though they look very similar, that the 12c+ and the 15c LE are actually a little bit different.

The 20b and the 30b have some minor difference that allows the 30b F/W to recognize that it is running on a 20b chassis. On the 20b chassis, HP was a bit clever here and the 30b F/W runs in a reduced "20b" mode -- none of the 30b-specific functions run.

So, given that I own neither a 12c nor a 15c LE, that if you could get ahold of the 15c LE F/W, that it would not run on the 12c chassis.

Note that this is likely a one direction limitation. We have seen that 12c F/W does run on a 15c LE just as the 30b will run the 20b F/W.

Just a guess...

[Don Shepherd]

I would think the annunciators would be different.

[uhmgawa]

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I would think the annunciators would be different.

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The lcd glass used in the encore voyagers is identical to the
original versions w/r/t supporting the sum of all model
annunciators. However no voyager model actually uses all
annunciators except for the special case of the system test
which enables every software driven segment of the the display.

I found this simplification convenient, allowing use of a more
comfortable font for rendering annunciators in KEMU's graphic
display support as there is no reason to consume limited pixel
real estate for annunciators which aren't used in a given model.

[Katie Wasserman]

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The lcd glass used in the encore voyagers is identical to the original versions w/r/t supporting the sum of all model annunciators. However no voyager model actually uses all annunciators except for the special case of the system test which enables every software driven segment of the the display.

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This is true with the exception of the 12CP, it has different annunciators and uses all of them. It has larger digits too.

[NateB]

It has been done, with modification to the older hardware.

Video

I'd be interested in replacing the guts of an original, non-working 15c with the internals of a new 12c and flashing it with the 15c firmware.

Edited: 13 Oct 2011, 10:43 p.m.

[Todd Israels]

Thanks for the knowledgeable answers so far. It would be an awesome combination and appears to be possible. Maybe the 12C re purposing project could be restarted to accomplish this