Having an Arduino detect the accessing of specific addresses on EPROMs

Here's something I've been pondering for a while so I thought I'd throw it out there to the experts to see if it's feasible:

What I want to do is make an Arduino circuit that can play specific sound samples and take other actions when it detects certain EPROM addresses being accessed on another circuit board, in my case older coin operated arcade game boards (80's/90's era, like Pacman and such). What I'm wanting to do is be able to add additional sound effects, possible speech and other things to games that don't normally have them, having it cued by things such as the game displaying specific graphics like the player's character exploding, getting punched in the face, etc. I'm thinking that perhaps I could have it detect when the address pins of the graphics EPROM go high in the order to call up each of the graphics I want to cue off of.

Example: For the game Double Dragon = Player get's punched in the face - original game program calls up graphics image of character reacting to it - Arduino detects that address being accessed on that graphics EPROM and plays an audio clip like swearing, yelling "Ow!", etc.

Sound plausible? I'm hardly an electronics or Arduino genius so I'm open to the idea that I have NO idea what I'm talking about and it couldn't work the way I'm thinking.


Theoretically plausible. Hmmmm…

OK, so you have this river of memory addresses on your old game system, flowing by.

You want to detect specific addresses (or possibly subsets of addresses) and react to them.

I’m not sure you can do this with an Arduino without some external hardware.

Main question: How wide is that river (how many address bits?) and how fast does it flow by??

Hmmm… IsThere some other signal on that game system that tell when addresses are valid? Otherwise Lotsa Glitches.

Tell us more…

I think most of the 80's stuff is 8 bit, they typically used EPROMs like 2716, 2732, and 2764, I'm sure it varies but for what I can tell the speeds typically go from 250 to 450ns, so that probably gets you in the ballpark.

Perhaps you could piggy-back an EPROM on the existing EPROM and have each of the data pins provide a trigger to the Arduino. Or one pin for a trigger and 128 conditions represented by the other 7 bits.

Interesting thought! I'm going to have to take a look at some of the logic analyzer setups using Arduinos too, because that's basically what it would be doing, though instead of displaying what's happening it would be looking for specific activity and reacting to it.

The big problem with that approach is that the Arduino only has 8 bit ports and you need to capature all the address lines in one go. There would normally be 16 address lines.
I would build a bunch of comparators to fish out the required bit pattern and qualify it with the data valid signal.