I completed this a few weeks ago but forgot to post about it. Probably the worst, most difficult freeplay/HSS mod I ever set about making (high score save was easy, freeplay wasn't).
The original game programming is very confusing, mame doesn't emulate some of the hardware properly and there are some bugs in the original game that needed fixing (for example try entering your initials for a new high score when you've got it set in factory freeplay mode, you get about a second before it either asks you if you want to continue, or if that option isn't set then it returns to waiting for you to press start).
Freeplay is selected as usual using the pricing DIPs. Then just press P1 or P2 start when attract mode is running and a game will start, continue option also works if selected. Code is based on the Midway Old Version (the newer version has even more bugs). Reset high scores on power-up with one of the unused DIP switches (remember to turn it off once booted or else it will reset them every power-up!) If you go to test mode it will show you the status of the high score reset DIP in real-time.
The high score save version shows "FREEPLAY" on the screen in attract mode, there wasn't enough ROM space to do this in the freeplay only version.
Runs on my usual Z80 single ROM/HSS board and works on both Midway and Namco versions of the board. Freeplay only code is available separately and free of charge.
Onto the photos...
The original game programming is very confusing, mame doesn't emulate some of the hardware properly and there are some bugs in the original game that needed fixing (for example try entering your initials for a new high score when you've got it set in factory freeplay mode, you get about a second before it either asks you if you want to continue, or if that option isn't set then it returns to waiting for you to press start).
Freeplay is selected as usual using the pricing DIPs. Then just press P1 or P2 start when attract mode is running and a game will start, continue option also works if selected. Code is based on the Midway Old Version (the newer version has even more bugs). Reset high scores on power-up with one of the unused DIP switches (remember to turn it off once booted or else it will reset them every power-up!) If you go to test mode it will show you the status of the high score reset DIP in real-time.
The high score save version shows "FREEPLAY" on the screen in attract mode, there wasn't enough ROM space to do this in the freeplay only version.
Runs on my usual Z80 single ROM/HSS board and works on both Midway and Namco versions of the board. Freeplay only code is available separately and free of charge.
Onto the photos...