gtoal
commented
4 years ago There are two ways to do this: 1) put a lot of work into finding where the high scores are held in each game; or 2) save the entire RAM and registers.. the latter would allow you to resume the game exactly where you left off. Since the registers are not visible to the ARM in the cartridge, this would have to be done by simulating an interrupt and executing some code on the 6809 supplied by the vextreme. Preferably in some spare address space and not the 48K supported by the cartridge (we do support 48K, yes, and not just 32K?) All the code has to do is push any remaining registers, then transfer all ram to the cartridge via a RPC. That ram dump would then be associated with that image, and restored when the image was loaded. A bit of complicated shuffling would be necessary but it could be done. And only has to be done once, rather than manually for every game.
technobly
We'd like to have a way to save high scores for each game, in an easy to maintain sort of way. There are hooks for high score RAM location in the Vectrex BIOS that we can look at to see what the current high score is.
One way to attack this is to patch each game with the high score manager code, such that when the high score gets updated, the manager runs instead and allows for more custom things to be done. This is kind of tedious to maintain though, and is anyone really going to trust high scores from an Open Source Vectrex Multicart? :D haha...
So how about we make this simpler and just give the owner of the cart a nice simple way to store the High Scores like this: