[A83] R: Re: What is the problem with flash writes (in
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[A83] R: Re: What is the problem with flash writes (in
-----Messaggio Originale-----
Da: "Ronald Teune" <rtwolf@gmx.net>
A: <assembly-83@lists.ticalc.org>
Data invio: martedi 10 luglio 2001 19.19
Oggetto: [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?
well he messed up a little bit...
pretty print - printing in a easily read format:
eg.
__
\/ 3
---- instead of (./3)/2
2
and CAS = computer algebra system... used to do advanced maths stuff and
symbolic manipulation...
> >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)
> >>
> >>
> >>
> >
> >
> >
> >
>
>
>
>
References: