Sunday, September 28, 2003, 9:44:04 AM, you wrote:

DA> I posted some time ago regarding need for an e-Reader dissection. All
DA> the leads that turned up as a result of my post went nowhere,
DA> unfortunately.

If I am not mistaken (please correct me, if you will find any
mistakes), there are e-cards with classic nes games.
E-reader scans them, saves data in internal flash memory (2MB,
right?), and allows to run them from now and until deletion from flash
memory.

This info was taken somewhere from Nintendo's official site. Hope I
remembered everything right.

So, how can e-reader run stored games (I mean games retrieved from
e-cards)?
I see two ways: first is running directly from flash memory (in case
it is connected as in flash cartridges and available at 0x08000000+x and
further), as "normal" flash cartridges allow multiple games running on
them; and second is copying game data to EXRAM (sized 256 kb) and
running game from it using standard technique.

Another "fact" is that in both cases game data should contain correct
header (with Nintendo logo, etc). (Is it right? Or am I mistaken?)

And here we also have two ways: header contains in data encrypted on
e-card, and header is added automatically by e-reader software.

Finally: if flash memory is accessible at 0x08000000+x then it can be
downloaded with any flash cart reader/programmer (i.e. GB tranferer 2
from EMS). If game is first transferred to EXRAM, and then executed,
then we can (I a not sure, that this will work, but the idea should be
clear to understand) add battery supply for EXRAM chip, so that the
data won't be deleted after switching GBA off. After that you insert
cartridge with small program that lets you transfer data from EXRAM to
computer (i.e. via link cable, or just transferring data (piece of
data) to SRAM, that can be read with software included with this
cartridge).

OK, hope we got data.
Next, if header is encrypted on e-card, then it seems that all e-cards
with games should have similar areas (this is Nintendo logo, etc).
If they don't, then header is added by e-reader software.

In any way, we can (in case I did not make many mistakes. Ha! ) say
that on this particular card(s) encrypted this particular data.

If I understand what I say (D-oh!) then task becomes muuuch easier, as
you know, what you should get after decrypting.


PS. If header is on e-card, then we do not need the whole game, as we
know what the header is.

PPS. If this dotcode is "heavily" encrypted (i.e. with key, that is on
the card, or something else similar), then we are stuck. Gosh!

PPPS. It is necessary to find out how bytes are read: from left to
right and up to down, or from up to down and left to right, or from
center to corners, or...


Hope this will help somebody.
And thanks for reading so far! ;)

--
Best regards,
Leonid mailto:leprud@...