This is a high score save for Rush'n Attack by Konami. I actually wrote this score save several years ago (back in 2006), and I'm just getting around to posting it now. There wasn't a lot of interest in the game back then, but as the arcade collector age demographic evolves over time so do the games that they collect. I see this game getting much more attention lately on the KLOV forums, so now seems like an apt time to release this.
For this save you'll need to change two ROMs and replace one RAM chip with a non-volatile RAM.
The RAM chip you need to replace is unlikely to be socketed, so you'll have to remove the RAM and install
a 28-pin socket for the new NVRAM. This compact little PCB is a bit harder to work on than the older boards,
and desoldering pins connected to the power rails (GND and +5V) can be difficult without the proper tools.
If you don't have the soldering skills to do this, please find someone who does to do it for you.
An experienced tech can do the job in under 10 minutes. You perform these modifications
AT YOUR OWN RISK!!!
This is a Z80-based game with no encryption, so this score save was pretty straightforward.
I modified the RAM initialization routines to protect the high score table contents and changed the code that sets the gameplay high score display so that it reads its initial value from the table in RAM (rather than the hardcoded default contained in ROM). Then I added a conditional reset. I decided to try something different this time instead of using the DIP switches. I check for a button/switch combo on boot, so you don't need to open up the game to reset the high score table. It's something that is fairly unlikely to happen by accident, so your scores should be safe! If for some reason you need to reset the high score table, here's what you do:
Hold down the Knife and Shoot buttons while pressing up on the joystick when the game boots (until you see the title screen).
1) The 8K static RAM (6264 or equivalent) at location 10E
needs to be replaced with a non-volatile memory. If that chip happens to be socketed (yeah, right!)
then all you have to do is just pop out the RAM and plug in a NVRAM.
If not, then you'll have to remove the chip and install a socket to plug your new NVRAM into.
For the NVRAM you can use a battery-backed SRAM like the ST M48Z08 or M48Z18.
Once you've got the new chip installed you should test the board at this point to verify that your socket
installation is good. The game should play normal.
2) The new high score save ROMs are 27128 EPROMs, and install into locations
8C and 10C.
Remove the existing EPROMs and pop the new ones in. All done!
Price is $32 shipped in the US (international shipping available at additional cost).
Please email me to check availability before sending money.
For the do-it-yourself'er.
If you've got your own programmer you can just download the ROM images and burn them to 27128 EPROMs.
Donations are always appreciated. Buy me a beer (or two) to encourage further score save development. Thank you.