HP Forum Archive 20

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hp12C capability Message #1 Posted by Todd Israels on 13 Oct 2011, 8:48 p.m. 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!

Re: hp12C capability Message #2 Posted by Jeff O. on 13 Oct 2011, 9:45 p.m., in response to message #1 by Todd Israels Quote: Will the new 12c with arm processor take the firmware for the 15C LE? Yes. The hardware is identical. Quote: Does the 12C+ have enough memory space to make it possible to have a 12C, 15C and 16C rom on board... Is 128 kB enough?

Re: hp12C capability Message #3 Posted by uhmgawa on 13 Oct 2011, 11:29 p.m., in response to message #2 by Jeff O. Quote: Is 128 kB enough? 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.

Re: hp12C capability Message #4 Posted by Neil Hamilton (Ottawa) on 14 Oct 2011, 7:11 a.m., in response to message #2 by Jeff O. 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...

Re: hp12C capability Message #5 Posted by Don Shepherd on 13 Oct 2011, 10:21 p.m., in response to message #1 by Todd Israels I would think the annunciators would be different.

Re: hp12C capability Message #6 Posted by uhmgawa on 13 Oct 2011, 11:48 p.m., in response to message #5 by Don Shepherd Quote: I would think the annunciators would be different. 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.

Re: hp12C capability Message #7 Posted by Katie Wasserman on 14 Oct 2011, 11:58 a.m., in response to message #6 by uhmgawa Quote: 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. This is true with the exception of the 12CP, it has different annunciators and uses all of them. It has larger digits too.

Re: hp12C capability Message #8 Posted by NateB on 13 Oct 2011, 10:40 p.m., in response to message #1 by Todd Israels 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.

Re: hp12C capability Message #9 Posted by Todd Israels on 14 Oct 2011, 12:20 a.m., in response to message #1 by 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

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