[A83] Re: What is the problem with flash writes (in general)
[Prev][Next][Index][Thread]
[A83] Re: What is the problem with flash writes (in general)
Nope, base codes need to be signed. I'm sure I wasn't the first person to
try to change some text in the base code and send it to the calc :)
-Dan Englender
----- Original Message -----
From: "Hyperbyte" <hyper@hysoft-automation.com>
To: <assembly-83@lists.ticalc.org>
Sent: Monday, July 09, 2001 4:46 PM
Subject: [A83] Re: What is the problem with flash writes (in general)
>
> This would ONLY work if TI had been so foolish as to not include
> the singing in Calc-To-Calc OS transfers.
> I'm sure they weren't that foolish!
>
> You're welcome to try though, but I'm sure it won't work.
> --(Peter-Martijn)
>
> >
> >
> > You don't need two calcs. You can also use a VTI to calc link and then
use
> > VTI's debugger to analyse things.
> >
> > The problem with simulating the computer though is that you first have
to
> > know what the computer does.
> >
> > ----- Original Message -----
> > From: "Dan Englender" <dan@calc.org>
> > To: <assembly-83@lists.ticalc.org>
> > Sent: Monday, July 09, 2001 10:12 PM
> > Subject: [A83] Re: What is the problem with flash writes (in general)
> >
> >
> > >
> > > I did something very similar to determine link commands for other
things.
> > I
> > > used Calcsys's Link Console (actually, I wrote the link console for
that
> > > purpose). And, assuming you've got a fairly new version of Calcsys,
you
> > can
> > > store the strings to reply with in RAM, and then send them by just
typing
> > > the address, instead of typing out the whole strings.
> > >
> > > If you have two TI-83P's (or know someone from whom you can borrow
one)
> > > you're in especially good luck You don't have to search through the
ROM
> > for
> > > the proper reply (something I wouldn't really suggest doing), but
instead
> > > you can use one of the calculators to simulate the computer, and see
what
> > > the reply is firsthand.
> > >
> > > Or you could build a custom program, whichever you want :)
> > >
> > > -Dan Englender
> > >
> > > ----- Original Message -----
> > > From: "Tijl Coosemans" <tijlc@hotmail.com>
> > > To: <assembly-83@lists.ticalc.org>
> > > Sent: Monday, July 09, 2001 4:09 PM
> > > Subject: [A83] Re: What is the problem with flash writes (in general)
> > >
> > >
> > > >
> > > > You should write a receive program for your calc, which displays
what
> > byte
> > > > you received from the graph link software. Then by examinig the
TI-OS
> > and
> > > > see how that would respond you can make your receive program a bit
> > > complexer
> > > > as to receive and examine more bytes. And so you continue. And then
> > > > (theoreticaly) you should be able to find what format your OS-file
> > should
> > > > have.
> > > > ------------
> > > > Hmm, this sounds a bit to easy maybe, but at least somebody could
try it
> > > > out.
> > > >
> > > > ----- Original Message -----
> > > > From: "Tijl Coosemans" <tijlc@hotmail.com>
> > > > To: <assembly-83@lists.ticalc.org>
> > > > Sent: Monday, July 09, 2001 9:55 PM
> > > > Subject: [A83] Re: What is the problem with flash writes (in
general)
> > > >
> > > >
> > > > >
> > > > > > From: "Hyperbyte" <hyper@hysoft-automation.com>
> > > > > >
> > > > > > > > From: "Hyperbyte" <hyper@hysoft-automation.com>
> > > > > > > >
> > > > > > > > Simply put, no user-program can do it.
> > > > > > > >
> > > > > > > > Explanation:
> > > > > > > > The flash chip has a "write enabled" line,
> > > > > > > > only if this line has specific signal, one can write to the
> > flash
> > > > > > > >
> > > > > > > > Now one could simply set this signal, if TI hadn't prevented
> > that,
> > > > > > > > they've somehow made it only possible for certain OS
Rompages to
> > > > > > > > set that value.
> > > > > > > >
> > > > > > > > (I think it's kinda obsolete now, since TI's released the
app
> > > > signing
> > > > > key,
> > > > > > > > but I doubt they'll insert _FlashWE and _FlashWD romcalls in
new
> > > > > OS'es)
> > > > > > > >
> > > > > > > > You could hardware hack that WE line, but then your program
> > > wouldn't
> > > > > be
> > > > > > > distributable...
> > > > > > >
> > > > > > > Or, you can make your own OS, I mean TI-OS, which implements a
> > > routine
> > > > > that
> > > > > > > enables writing to flash......
> > > > > >
> > > > > > How are you planning on signing that custom 'TI'-OS?
> > > > > >
> > > > > > 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.
> > > > >
> > > > > It's all theoreticaly of course, but when you attempt to send an
OS to
> > > > your
> > > > > calc, your calc checks if it's a valid OS right? So can't you
check
> > that
> > > > > code and see how that's done? It's also possible that the graph
link
> > > > > software checks a few things, but writing your own PC program that
> > sends
> > > > > data and doen't check anything shouldn't be that difficult.
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> >
> >
>
>
>
References: