First off, I'd like to thank Francis Mariani (user "nash" on the KLOV forums) for his generous contribution that funded the development of this high score save. Without his help and occasional prodding, this wouldn't have happened.
This is actually two things in one: an upgrade to Assault Plus, and a high score save. Assault Plus is essentially an update to Assault that fixes some bugs and adds some features, like a choice between two different games at start and 2-player alternating play support (you would need to add a 2P Start button to take advantage of that). There are few other changes as well, like different music and some minor color changes. It is a more polished version of the game (it is my understanding that the original game was rushed to market).
This kit is plug-n-play! Installation is simply a matter of replacing two chips on the board; MPR0 at location 11D, and MPR1 at location 13D. The new chips will be larger and fill the entire socket. The only thing you need to worry about is the chip orientation, and that should be obvious by the notch and label.
For resetting the high score table, I wanted to use something that wouldn't happen accidentally, yet didn't require you to dig into the back of the game (like flipping DIPs). So I decided to use the coin switch on boot. So if you find the need to reset the high score table, this procedure is simple and only requires coin door access:
The default scores are restored.
Price for this score save kit is $40 shipped in the US (international shipping available at additional cost).
The chips I'm using are reprogrammable flash, so if an update is ever done you can send them back to me and I will update them for free (just pay return shipping).
The first two runs of these are sold out, but I still make them on-demand. That just means they may not be ready for immediate shipment, so you may have to wait a week or two while I source and purchase the parts. Please contact me if you would like to order.
Ah, but there's more! As an added treat, I hid the original Assault code in there too. Modified to save scores as well too! It just takes a little DIY hacking to unlock this. Then you can quickly and easily switch between the two versions if you so desire. Each game keeps its own independent high score table. Info on enabling the multigame is here.