[Coco] About those EPROMS...

[Mark McDougall]

On 10/04/2015 10:44 AM, Dave Philipsen wrote:

> Yes, I used to work on arcade video games back in the 80s and I don't
> remember which game it was but I remmeber looking at the schematic and
> wondering why all that extra circuitry existed between the processor and the
> EPROMs.  In reality, though, all you would have had to do was to plug in
> some sort of emulator into the processor socket and you could read the code
> from the EPROMs if you wanted to disassemble it.  I've also seen circuits
> where the address lines and data lines were all scrambled around....not too
> hard to figure out, but....

Yes, you look back at some of them and wonder - why did they even bother? 
Pretty silly putting a protection scheme on a PCB that is rendered 
completely ineffective almost implicitly in the process of cloning the board 
- one of the very activities it was designed to prevent!

Regards,

-- 
|              Mark McDougall                | "Electrical Engineers do it
|  <http://members.iinet.net.au/~msmcdoug>   |   with less resistance!"