[vcf-midatlantic] help dumping rom of rare coin-op arcade game

Dan Roganti ragooman at gmail.com
Fri Mar 17 06:23:21 EDT 2017

On Thu, Mar 16, 2017 at 10:50 PM, Ethan <telmnstr at 757.org> wrote:

> ​this is the first I've heard about arcade roms being encrypted
>> ​most of the time it was painstaking to decipher the bitmaps for their
>> background screens, or sprites
>> because the address boundaries of the bitmap images had to be extracted
>> from the code
>> and that's after you disassemble the machine code
>> Dan
> I think it was more of the later games that used heavy encryption. Things
> like the CPSII which just finally got fully reversed (there are tools to
> reprogram the crypto keys into the hardware now.) Other games such as
> Arkanoid use a one-time-programmable microcontroller that looks like an
> EPROM to answer some sort questions for the main CPU. All kinds of tricks.
> Current generation machines are being popped by using PCI-E DMA exploits
> to recover security keys used by the SATA controller chipsets and other
> crazy stuff on Linux/PC based systems. The hard drives require some sort of
> unlock command every so many nanoseconds or something.
> My go-to programmer I have here is the Needham Electronics EMP-100. Hollar
> if I can be of any assistance!
>                         - Ethan
​oh that yea,
But we never called it encryption,
it was really a form of copy protection, but then done in hardware
Because the bootleg market was intense since the late 70s​.
I don't recall every protection scheme, just some of the earlier ones
That one with the microcontroller rings a bell,
It wasn't so prevalent in the 70s and 80s,
But it sticks out like a sore thumb when looking at the schematics

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