thank you a lot for checking the code - I am very happy that the USER subroutine now works as intended.
I will add "USER command 0" to the code when I have investigated how to deal with the software dips.
Could you please explain some more details about the location of the credit counter which depends on the system mode ?
According to the neogeodev wiki the credit counters are located at 0xD00034 to 0xD00035, thats why I have read the data from this location.
But it seems both counters (for Player 1 and Player 2) are aggregated in a "BCD" format. Does BCD mean "Binary Coded Decimal" and if yes, is there a way to display it properly?
Sources:
"$D00034 to $D00035 "Internal" credit counters for player 1 and player 2 (BCD)" (https://wiki.neogeodev.org/index.php?title=Backup_RAM)
"Credits can be read through $D00034 and $D00035." (https://wiki.neogeodev.org/index.php?title=CREDIT_DOWN)