23 Jun
2013
23 Jun
'13
11:53 p.m.
On Mon, 24 Jun 2013, emu wrote:
Quoting Jim Carpenter <jim at deitygraveyard.com>:
That's possible, but the image is loaded via MOP or tftp...so that'd
either require instructions to flip the bits or an executable to flip
them, no?
Or....off the flash card.
The data in xpcs00s.sys is almost certainly
compressed. That's why you
can only find a couple strings in the whole thing. You'll have to
decompress it somehow first. Then you can disassemble it.
Just a shot in the dark, but the cheapest copy protection is to flip some
bits on the data bus. If you read a PROM on a programmer, all you see is
garbage, until you figure out how the data bus was connected.
Usually, nobody wasted the money to copy the ROM into
an expensive SRAM
to run it ...
Cheers
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects