The RAM address for the IGT is 0x1C3030 that's for the English version. All the known addresses are included in LegnaX's autosplitter! https://github.com/Legnax/Oddysee-Autosplitter/blob/master/Official%20Oddysee%20Autosplitter%201.1.asl
There's also a DOS version that has much louder audio some folks suggest I should try on the DOS version... https://drive.google.com/file/d/1cIyqj9r1EwzOEPQpKRGRgbd1wjp2LTTZ/view?usp=sharing