If it’s physically impossible to write to a ROM (read-only memory) cartridge, how do manufacturers do it?

Question

Is somehow locked physically during production, or through software?

In: 210

Answer 1

They are generally not able to be written to by the device that they’re meant to be in. This doesn’t mean they can never be written to ever. It means that the circuitry to read from them is different from what is needed to write it or that it can be written to once. Write once can literally have severing circuits that fuse off and can never be used again after writing.