Great thread! Here are some facts about MK3 and UMK3 Wavenet that i got from various people and old internet sources:
1. WaveNET Stands for Williams (! not Midway) Action Video Entertainment NETwork
2. UMK3 Wavenet - You need 3 tokens to start, then after 10 wins, the message: "Kontinue your Winning Streak!" comes up, and you have to put in 2 more tokens to continue playing, and then every 5 wins after that, you have to put in two more tokens to continue.
3. UMK3 Wavenet - When u try an infinite combo (Kung Lao's or Stryker's) a whistle will blow and say "Stop Cheating" and a few others messages, including KMD. What KMD is, I doubt someone know lol
4. UMK3 Wavenet - Hall of fame - Wait for the "MK3 Wavenet Edition" screen. Press and hold at that moment start, right, and the rest of the buttons except for LP. Keep holding till it happens, if you see the demo, then something went wrong, try again. The screen starting flashing through different stages. Like it does when u put in a UKK. Then Raiden, Rain, and Noob popped out and perforem their winning stances. Then a MK1 and MK2 arcade machine fell behind them.
5. UMK3 Wavenet - Do the same as the above one, but instead of doing it on the title, do it before the title. You'll notice that instead of "Wavnet Edition" it'll say "Nitro Edition".
6. UMK3 Wavenet - Before the machine boots, press and hold RUN, once it boots, instead of saying "Downloading Wavnet Data", it'll say "Rewinding Cassette Deck".
7. In UMK3 Wavenet people claimed that you could perform Babality AND Mercy, however, this is not working in Revision 1.1 and 1.2. In MK Trilogy for N64 you can perform Friendship and Mercy.
8. MK3 Wavenet probably had some gameplay changes as well, because people said Cyrax's throw juggled the foe higher, and Nightwolf's 3rd axe has difficult times to connect.
9. The Wavenet was implemented for Mortal Kombat 3 and San Francisco Rush somewhere in the spring of 1996. Somewhere around August for UMK3.
10. MK3 used a really weird processor called a 34010 from Texas Instruments. However, the game designers pretty much pushed the CPU to its max before the Wavenet Group (thats the team for Wavenet) had a chance to make it a networked game. There wasn't enough RAM, CPU, or ROM (for networking code) left to do it, as well as this board didn't have an ethernet output on it to connect it up to the router. Midway ended up designing a tiiiiny little board (running a small embedded OS that just translated game commands into TCP/IP and vice versa) that plugged into an expansion connector on the MK3 board. It had an Ethernet controller, some ram, more ROMs for the networking code and a 386SX CPU made by AMD on it.
11. UMK3 Wavenet gameplay changes had Kung Lao's Spin disabled after 3 hits, Stryker's Gun after 5 hits, before Kabal performs his Spin you hear a sound.
12. UMK3 Wavenet - There was an option to change your nickname during the match, and some players often did that so they dont get the loss.
13. Unconfirmed stuff - Ermac's TKS had larger area. You can do 99% combos but, then it just stops doing damage, the opponent will stay on danger no matter if the juggle continue. 12 Wavenet UMK3 machines and 8 MK3 Wavenet Machines total. Noob Saibot's Teleport move had a hit limit.