[TI-H] Re: building a TI92plus module
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[TI-H] Re: building a TI92plus module
On Fri, Dec 27, 2002 at 01:53:49AM +0100, docydoc wrote:
> Hi!
>
> > Can you find out that article, please? It would be interesting.
> > However I think that protection is not strictly necessary to have it
> > working; what do you think?
>
> I don't know for sure where I've found it but I'll keep an eye on it.
I think I've found it:
http://tict.ticalc.org/docs/flashrom.txt
> No, not strictly necessary but some evil programs might overwrite your FLASH and
> that
> is not so nice. Even if a program does not intentionally at least an external
> switch should
> be used to protect some areas (e.g. the certificate's area and boot-strap if it's
> inside there)
Moreover, I've read in that doc that the ti won't boot if there isn't
the orbit chip prtection :((
> > There are some informations that I need but I couldn't find: how the
> > ti-92 addresses the external rom and ram: addresses and wo4rd length (it seems
> > 16 bit words, al long as there isn't a0 and there are 16 data pins, but
> > on one of ther previous links there's a 8 bit memory chip connected.
> > I'm asking the authors...
I've read RAM is interleaved! That explains why ram chip is connected
starting from a0 and to d15_d8!
I suppose ROM is addresed 16 bit at once. I've read the TI-89 has a
LH28F160, that can be addressed 1Mbx16. But the chip on the picture of
the Plus module you sent me there's a LH28F016, that is addressable only
as 2Mbx8... so.. I still don't understand...
It whould be interesting to have a scheme of the plus module...
Bye,
Ludovico Cavedon
lumaca82@inwind.it
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