I watched this video about the anti-piracy measures of the PS1 and Spyro 3.
The tldr is that PS1 disks have a special region of the disk that is not readable by any other disk reader on the planet. This part of the disk contains region information (NA, JAP, etc...) and if it's not there, then the disk was created using a run-of-the-mill disk burner, and is therefore not legitimate.
Some smart people found a way around this by creating a special chip that would intercept the region request and return the correct information. This fooled the PS1 into thinking the disk is legitmate.
Unfortunately, the PS1 is designed such that this region information is only available as the game is booted. If the game is running, then this information should not be accessible, but the special mod chip would return the information regardless.
Some developers used this to detect if their game was being run on a modded PS1, and would write special logic to sabotage their game if it was running on modded hardware.
How does an emulator, like pcsxr, deal with this? Does it just naively return the region information all the time?