24 Jun
2013
24 Jun
'13
2:40 a.m.
Quoting Jim Carpenter <jim at deitygraveyard.com>:
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
24 Jun
24 Jun
2:53 a.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
3:04 a.m.
Quoting Cory Smelosky <b4 at gewt.net>:
As I said, it was very dark ;-)
If you download it and run it from RAM, it could be encrypted ...
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.
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.
> Usually, nobody wasted the money to copy the ROM into an expensive SRAM
> to run it ...
3:09 a.m.
On Mon, 24 Jun 2013, emu wrote:
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
Quoting Cory Smelosky <b4 at gewt.net>:
As I said, it was very dark ;-)
If you download it and run it from RAM, it could be encrypted ...
True. It's a 6800 though...encryption would add quite a bit of overhead.
;)
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.
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.
> Usually, nobody wasted the money to copy the ROM into an expensive SRAM
> to run it ... 
11:15 a.m.
Just a shot in
the dark, but the cheapest copy protection is to flip
some bits on the data bus. [...]
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? > Usually, nobody wasted the money to copy the ROM
into an expensive
> SRAM to run it ...
Perhaps not back in the day, but it's not uncommon now. I have an SMC
switch which does that - which decompresses its flash-stored image into
RAM for operational use. Of course, anything using a 6800 as its main
CPU probably does go back that far....
/~\ The ASCII Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents-montreal.org
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
1:31 p.m.
On Mon, 24 Jun 2013, Mouse wrote:
Only if you insist on the network-loaded bits being identical to the
bits stored in the PROM.
Hmm. Right.
Dates to 1995. :)
Just a
shot in the dark, but the cheapest copy protection is to flip
some bits on the data bus. [...]
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? > Usually,
nobody wasted the money to copy the ROM into an expensive
> SRAM to run it ...
Perhaps not back in the day, but it's not uncommon now. I have an SMC
switch which does that - which decompresses its flash-stored image into
RAM for operational use. Of course, anything using a 6800 as its main
CPU probably does go back that far....
/~\ The ASCII Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents-montreal.org
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
4051
days inactive
4051
days old
5 comments
3 participants
participants (3)
-
b4＠gewt.net -
emu＠e-bbes.com -
mouse＠Rodents-Montreal.ORG