Omnimaga
Calculator Community => Other Calc-Related Projects and Ideas => Topic started by: wideruled on February 07, 2011, 07:41:34 pm
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Hi Omnimaga forums, I have a Ti-84+ that I've owned for a few years and am wondering if anyone has had experience swapping the NAND from these calculators. What's currently in my calc is a 29LV800 (a 8Mbit NAND) and just found a 29LV1600 (16Mbit/2Mbyte NAND) in a leapfrog cartridge I bought cheap from a thrift store. I know that the Ti-84+ Silver edition use a 16Mbit NAND so would there be any problems in swapping the NAND and flash a dump from a Silver edition?
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Compare the PCB and chip connections on http://www.datamath.org/ .
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I'm not skilled in the area of raw hardware, but considering that the only tangible difference between TI-84+ and TI-84+SE is the flash chip size, this might be possible.
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That would be awesome if you could do it.
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You'll have to program the TI-84+ 1.00 or 1.02 boot code image in the NAND.
By the way, how does the TI-84+ OS detect the NAND capacity?
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You'll have to program the TI-84+ 1.00 or 1.02 boot code image in the NAND.
By the way, how does the TI-84+ OS detect the NAND capacity?
I believe through one of the ports. Which one though, I'm not sure.
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if it would be possible, it would be epic :D
but is it then also possible to insert a flash chip of 2gb or so?
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if it would be possible, it would be epic :D
but is it then also possible to insert a flash chip of 2gb or so?
No.
We might be able to replace the 1Mb flash chip in basic TI-84+ by a 2Mb flash chip, only because they seem to be using the same PCB as the TI-84+SE which allready have a 2Mb flash chip.
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You'll have to program the TI-84+ 1.00 or 1.02 boot code image in the NAND.
By the way, how does the TI-84+ OS detect the NAND capacity?
I believe through one of the ports. Which one though, I'm not sure.
It actually detects whether it's a TI-84+ or a TI-84+SE by one of the ports which is set manually by the boot code. Therefore, using a NAND with a TI-84+SE boot code installed should report the new size just fine. I do have to wonder, though, whether the boot code is run from page 3Fh or 7Fh (mirror of 3Fh) on the TI-84+. If it's 7Fh, then there should be no problem I think. Since TI made the hardware identical to TI-84+SE in every other way, it's not implausible that this might be the same too.
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if it would be possible, it would be epic :D
but is it then also possible to insert a flash chip of 2gb or so?
No.
We might be able to replace the 1Mb flash chip in basic TI-84+ by a 2Mb flash chip, only because they seem to be using the same PCB as the TI-84+SE which allready have a 2Mb flash chip.
pity :(
but now i won't spam this topic anymore ;)
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I thought that I'd have to switch some resistors around to specify capacity on the hardware level (the Xbox360 determines the size of NAND installed that way) but the datamath images are identical. That makes my job a little easier. Once I get the new NAND installed, I'd have to find a dump from an SE. I imagine that asking for a NAND dump would get me nothing, so is there any way to modify a ROM dump from my calc to work, if anyone has the experience?
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Once I get the new NAND installed, I'd have to find a dump from an SE. I imagine that asking for a NAND dump would get me nothing, so is there any way to modify a ROM dump from my calc to work, if anyone has the experience?
Dumping the data from an SE can be done using software, no hardware modifications needed. I'm not sure if you just need the two boot pages or if you need a full flash dump. Does anyone know if the certificate/swap sector/other stuff are in different locations on the SE?
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I thought that I'd have to switch some resistors around to specify capacity on the hardware level (the Xbox360 determines the size of NAND installed that way) but the datamath images are identical. That makes my job a little easier. Once I get the new NAND installed, I'd have to find a dump from an SE. I imagine that asking for a NAND dump would get me nothing, so is there any way to modify a ROM dump from my calc to work, if anyone has the experience?
You only need to flash the boot code and certificate sectors.
Then you should be able to install an OS from the computer or another calculator.
And remember Datamath is not showing photos of the other side of the PCB...
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You only need to flash the boot code and certificate sectors.
Then you should be able to install an OS from the computer or another calculator.
The certificate of an 84+ can be used if it's moved to the correct location, right?
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You only need to flash the boot code and certificate sectors.
Then you should be able to install an OS from the computer or another calculator.
The certificate of an 84+ can be used if it's moved to the correct location, right?
It's true for the boot code, which is identical.
I don't know about the certificate...
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You only need to flash the boot code and certificate sectors.
Then you should be able to install an OS from the computer or another calculator.
The certificate of an 84+ can be used if it's moved to the correct location, right?
It's true for the boot code, which is identical.
I don't know about the certificate...
No, the boot code of the 84+ and the 84+ SE are different.
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You're right.
Sorry, I hadn't checked those dumps for over a year.
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Obviously specific software would have to be written to take advantage of this, but couldn't a 4MB or 8MB chip be installed and then have a switch installed to swap out the page sets?
I'll just explain the 4MB for simplicity. You install the 4MB chip and have the highest pin tied to a physical switch that is default on. Then you load the OS and certificate and boot sector into the 80 - FF range, which the calculator just sees as 00 - 7F. So like this, the calculator would be completely normal. But now, you flip the switch and have access to the first page set which could be used for archive purposes. Obviously things would have to remain in RAM when the pages are swapped, but I don't really see any problems with this idea. You could even make a boot page and page 0 so that if a ram clear occurs, it would give a message to flip the switch.
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That ^ would be more difficult, but plausible. You would have to have a hardware flasher to flash the chip, though, correct?