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Has anyone with the new 12c attempted to download firmware from the 10c, 11c or 16c onto it?
I.e. find where the original 12c ROM lives in the image and replace that with a ROM image for one of the others.
The 15c is less likely to work since the ROM is twice the size.
- Pauli
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Interesting...how would you do it?
As I understand the 12C+ (not having found one yet), there is no JTAG port, so no way to pull the existing firmware out as we did with the 20B. Booting into the AT91SAM7L128 serial bootloader will erase the firmware from the calc.
Once you have the firmware, you'd still need to find the 10C, 11C, or 16C image. Last time I checked, they'd been removed from the nonpareil distribution. (Which leads me to think that it might still be a fun project, yet not something that could be publicly distributed without upsetting someone...)
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Quote:
As I understand the 12C+ (not having found one yet), there is no JTAG port, so no way to pull the existing firmware out as we did with the 20B. Booting into the AT91SAM7L128 serial bootloader will erase the firmware from the calc.
That's all correct.
It's also possible that there are some patches to the original 12c firmware to handle certain timing issues -- I'm just speculating on this based on some comments Cyrille made here in the past.
However it's still a neat calculator to re-purpose even if you have to start nearly from scratch. It's in the perfect format with a highly readable display and great keys not to mention a very fast processor.
-Katie
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I think we should work to get Scott Newell an HP 12c+.
That will go a LONG way to getting us a scientific in a voyager case.
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I think we should work to get Scott Newell an HP 12c+.
That will go a LONG way to getting us a scientific in a voyager case.
Don't be too sure. I've got a bad habit of starting projects and losing interest or never finishing them. After all, it's been what, 2+ years since I did any 20B hacking?
I think I've got a line on a 12C+. Should know by the weekend.
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Scott,
Let me know if you want a beta tester, or even an alpha tester.
-Katie
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I think I've got a line on a 12C+. Should know by the weekend.
I now have a 12C+! I may play with it a day or so in stock form before hacking it, since there's no way (yet?) to restore it to a 12C.
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It's also possible that there are some patches to the original 12c firmware to handle certain timing issues -- I'm just speculating on this based on some comments Cyrille made here in the past.
Same thoughts here. I've also wondered if maybe the emulator got tweaked a bit to save power when the calc wasn't busy.
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I thought the rom of the 12c was really big--to handle all the financials. You say the 15c rom was bigger? Is this a fact, or speculation?
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The 11c, 12c and 16c all have the same ROM size (about 55,000 bytes) while the 15C's ROM is twice as big. ROM in the ARM chip that HP is currently using (AT91SAM7L128) is 128K and given that you'd need the emulator in there too it would be hard to fit without some sort of compression. There's a similar 256K chip (AT91SAM7S256) but it has a higher current draw and would have to run a a lower speed and have a shorter battery life in the off state.
-Katie
Edited: 28 Apr 2010, 11:41 a.m. after one or more responses were posted
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The 11c, 12c and 16c all have the same ROM size (about 55,000 bytes) while the 15C's ROM is twice as big. ROM in the ARM chip that HP is
From what I remember of the ROM files in the old nonpareil distribution, that's not correct. I think they are much smaller.
Maybe Eric Smith will chime in.
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The 10c, 11c, 12c and 16c used 6144 (0x1800) 10-bit words of ROM.
The 15c used 12288 (0x3000) 10-bit words of ROM.
RISC might be fast but it sucks big-time for code density.
Edited: 28 Apr 2010, 1:17 p.m.
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The 11c, 12c and 16c all have the same ROM size (about 55,000 bytes) while the 15C's ROM is twice as big.
The nonpareil ROM images are 55k but are text in a not even remotely compacted format: 4 digits of address, a colon, three digits of code and a new line. i.e. 9 characters per ten bits. Looks like about 6150 lines of real code there.
Anyway, the reason I thought the 15c firmware would be harder isn't due to it fitting or not, there should be plenty of flash space free. Rather, it would be due to there not being space to just dump it into the firmware in place.
We need to get a flash dump somehow to experiment :-)
- Pauli
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Quote:
The nonpareil ROM images are 55k but are text in a not even remotely compacted format: 4 digits of address, a colon, three digits of code and a new line. i.e. 9 characters per ten bits. Looks like about 6150 lines of real code there.
Yes indeed, I stand corrected.
I count 14,336 10-bit words in the 15C emulator image, but some of this might be more than in the original ROM.
-Katie
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The 10C, 11C, 12C, and 16C ROM is 61440 *bits*, which is under 8K bytes.
The 15C has two ROMs of that size.
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Are HP prepared to give out the current 12C+ rom image. this would be so as to flash the new 12c+ back to being a calculator after hacking?
would like to try some hacks.
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I rather doubt it, but I'm not in any better position to know than you are.
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