Genesis AT&T Edge16 Modem

Just thought id update this here again, i did receive word from the same person i talked to before about these units. He said that he desn't believe that an Edge Card was required for game play, or that it had any firmware on it from his recollection. They were designed to basically hold data from games. For example, if you got to a certain level in a disney game, you could take the card to a disney store and redeem for free gift or something of the sorts. They were encrypted as well....

 

The games probably are missing the code to check for the modem, or they are just noped. Can you patch the rom to always show the modem option instead?

 

At least we've got something out of it, right?

 

Well the stuff that's in the Ballz manual about the modem means it definitely made it into the game and should detect the modem. I'm waiting for a copy of ballz to show up so I can test it out. brutal paws of fury doesn't seem to acknowledge the modem and show the menu option. it's possible the graphics remain in the game for the modem option but the code was removed maybe.

 

Do you think a real cart will behave differently?

 

I'm not sure. Im inclined to say no, but i guess its possible that it may try to check for something specific on a production cart. Or perhaps maybe the mega-everdrive im using is causing some sort of problems.

When i used the hacked codes i posted previously on a flash cart with the ballz rom image on it. The modem option shows because i've activated it, but after selecting it. The sound goes dead and the game just freezes... Modem doesnt seem to show any changes with the lights or anything. Unsure here..

Edit: A copy of ballz i purchased just showed up. Tried it and no difference. Not sure whats up really. The manual for ballz states that the modem menu option should show up and once selected it should show the edge dialer screen. oddly when this is enabled via game genie hacks and select it, the game freezes. Wondering if maybe its trying to load content from the edge modem?
Anyhow, looks like ripping apart the ballz rom to see whats going on might give clues.

Im not entirely sure the code in ballz or brutal paws of fury to detect the modem are even present!! the menu stuff seems to still be there but this looks like a job for someone with more time than me.

 

I remember that game (Ballz) would lock in Genesis Plus GX because it tries to access $a113xx memory area which was considered as an illegal area. It's very likely the modem is mapped in that memory area and the game tries to detect it then communicate with it through this on startup. Your patch probably faked the detection part but the communication protocol with the modem is failing since it's not emulated.

 

you happen to know which address exactly that it tries to access?

the modem without power won't let games boot, but with power it works like a normal genesis with game plugged in. I'm guessing on boot the modem is mapped and the adress should be able to be read or written to.

I havnt had any chance to view any of the code leading up to the menu loading to see if a normally invalid adress was checked against