Motivation I came across a Teenage Mutant Ninja Turtles (TMNT) board recently. The TNMT games on Konami boards are very iconic both in their 4 player and 2 player forms. According to the listing the board was "Tested, working" and the seller even did a retest prior to sending which reported on "Retested, working". So all great... until it arrived. Upon testing, I realized the inputs were not working properly. Buttons were mostly okay, but only the left direction was working, and the same afflicted the input 2. I thought that it could be some sort of non-standard JAMMA input mapping, and even replaced the EPROMs with the 2 player version of the game, but problem persisted. Understanding the problem Finally I decided to take a look at the schematics. On page 17 of a PDF manual I downloaded, I found the input section, which looked like this: Okay, so it looks like all inputs go through a component labeled 005273, which are labeled RN1 to RN10. And guess what? it se
The background story I love Thunder Force games. My first experience was with Thunder Force III on the Mega Drive, and then Thunder Force IV. Later on Thunder Force V on Saturn was my last experience with a Thunder Force game... until emulation came around that is. My curiosity first took me to Thunder Force II on the Mega Drive, which was a mixed experience, having played its successors before it. But later, while digging SEGA games to play on MAME, I found out about Thunder Force AC, which is mostly Thunder Force III, with a few differences. The game is nearly identical so there wasn't anything remarkable about it at the time. From emulated to real arcade games After I decided to build a System 16 game I purchased an Altered Beast board to start doing the experiments needed to develop a DevKit. That sparked the interest in knowing and understanding arcade boards, especially those made by SEGA. Among those was the System C. It's a board that shares many commonalities with t