[A83] Re: What is the problem with flash writes (in general)
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[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.
> >
> >
> >
>
>
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