NHL '94 Goal Light Cartridge

[McMikey]

Hi guys,

 

If you haven't seen it yet Dave from Dave's Geeky Hockey made a post about adding a Budweiser style goal light to an NHL'94 cartridge. You should go read that article now. Dave is the mastermind who is always coming up with amazing ideas and products. I'm a huge fan. Just now we had a little back and forth on twitter about actually MAKING THIS and he brings up a great question. Can the light be coded to physically come on when a goal is made in the game? 

Are there other ways to do it?

-I suggested a button on the controller.

-An active listening device set to activate the light when it hears the goal horn.

But like Dave mentioned to me on Twitter.

"An active listening device would take up too much power.

Something that is triggered by game code would be more elegant."

@davesgeekyideas

 

What are your guy's thoughts on this? Can it be coded to activate the light?

 

Cheers,

 

Mikey

[jer_33]

I am not a coder or electronics guy, but I assume that if there is two-way communication between the cart and the system, that whatever code triggers the system to play the goal music should be able to trigger another event (like a flashing bar of red leds). You would have to have an internal power source to power the leds, but it would all be a pretty low power draw.

This has me thinking. I wonder if we could code a button on the 6-button controller to play the "crowd booing" sound on demand? Kind of like some of the old Superchexx games.

 

Edited August 10, 2018 by jer_33

[smozoma]

So I don't have practical skills in this matter, but this is the way that comes to mind:

1. Figure out which contacts on the cartridge are for specifying which bytes are being read from the cartridge. (http://www.hardwarebook.info/Mega_Drive_Cartridge)
2. Make some kind of simple "AND" circuit that corresponds to an instruction offset/address in the ROM that is only executed when a goal is scored (such as the goal siren playing or the score incrementing, which could be discovered using the debugging emulator's trace feature). 
3. When that circuit detects that the instruction has been accessed (which will only be for tiny fraction of a second, so I have no idea what kind of circuitry you're going to need to detect it), it outputs a signal in the ON state for a moment.
4. The light has a circuit that detects when that output signal switches ON, it activates the light for a set period of time, plays a sound, whatever.

There's probably some Arduino or Raspberry Pi hobbyist out there who thinks this is super easy, but I have no idea how to do it.

[smozoma]

1 hour ago, McMikey said:

-An active listening device set to activate the light when it hears the goal horn.

That might be do-able, with some kind of sound sensor hooked up to an arduino or raspberry pi, listening for a specific frequency. Set up the microphone right next to the TV speaker...

[jer_33]

57 minutes ago, smozoma said:

So I don't have practical skills in this matter, but this is the way that comes to mind:

1. Figure out which contacts on the cartridge are for specifying which bytes are being read from the cartridge. (http://www.hardwarebook.info/Mega_Drive_Cartridge)
2. Make some kind of simple "AND" circuit that corresponds to an instruction offset/address in the ROM that is only executed when a goal is scored (such as the goal siren playing or the score incrementing, which could be discovered using the debugging emulator's trace feature). 
3. When that circuit detects that the instruction has been accessed (which will only be for tiny fraction of a second, so I have no idea what kind of circuitry you're going to need to detect it), it outputs a signal in the ON state for a moment.
4. The light has a circuit that detects when that output signal switches ON, it activates the light for a set period of time, plays a sound, whatever.

There's probably some Arduino or Raspberry Pi hobbyist out there who thinks this is super easy, but I have no idea how to do it.

I'm no expert, but the code to run a small RaspPiZero with the light string would be the easy part (although you'd need a customized cart to fit it all in), it would definitely be mapping the cart to trigger the event that would be the tough part.

[Drezz]

The button on the controller might be the easiest since it would be more of a physical connection and less prone to bugs if you were hacking the ROM. You'd have to use a 6 button though.