[A83] Re: What is the problem with flash writes (in


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[A83] Re: What is the problem with flash writes (in




>...why would you want to overwrite the ROM in the first place? You can hook
>nearly everything you'd ever want from an app. Including that if you wanted
>to you could make a pretty print CAS like the 89 has with the hooks given.

What's a print CAS?

>This check is done in the boot code of the calculator.
>This boot code is loaded from real Read ONLY Memory.
>You could ofcourse remove the bootcode chip, and replace it, but
>I think that would be rather dangerous.
>
>Slightly better would be to hardwire the write enabled line to a
>write-enabled state, and then simply write the OS to it.
>(Would be nice to implement certain relly useful non-native math
>functions into your TI83+ without teachers noticing it at all.)
>
>--(Peter-Martijn)
>
>>
>> >AFAIK, OS'es need to be signed too, and I can't see how TI would be
>> >as stupid as to sign it's OS'es with the freeware private key.
>>
>>
>> Is this check for signedness a hardware thing or a software thing? Could
>an
>> approach like the HW2Patch for the TI-89 be used to override any check
for
>> a signed application?  If it is software, I don't see how a new OS could
>be
>> prevented from being put on the calc if you used a custom link program
and
>> did a total wipe of the flash chip ahead of time (hold a hot line to the
>> pin on the chip, if necessary)
>>
>>
>>
>
>
>
>




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