I have a Japanese Midnight Blue PS1, model SCPH-7000W. It plays legitimate imports but not copies/master disks. I'm wondering whether it is functionally a Yaroze - runs anything matching SCEx. However, I don't have a Yaroze boot disk to try on it. If it runs the Yaroze boot disk, it would mean that the Japanese midnight blue system is a Yaroze with newer firmware and laser unit. The SCPH-7000W has a unique BIOS that hadn't been dumped before. It looked like a slightly-older version of the SCPH-7001 firmware. Despite being a Japanese system, it is an American BIOS, probably so that the license sector check isn't present. The American midnight blue system is labeled SCPH-7501 and does not run imported games, according to someone I asked who has one of these. How is the PS1 Mechacon firmware dumped? That would also give a unique dump, most likely - a newer CD controller with Yaroze configuration. I don't know whether my midnight blue system accepts the unlock CD commands; I have no way to test this.
The US 10 million is SCPH-7001 (not SCPH 7501). There are 2 JP 10 million variations; the SCPH-7000W plays US and PAL discs, and the SCPH-7000 (without the W) only plays JP discs. The info above probably not helpful to what you are looking for but I just wanna correct the info on the US model.
Hmm. I wonder whether the SCPH-7000 midnight blue uses a Japanese BIOS. My SCPH-7000W uses an American BIOS, so it says "CD PLAYER" instead of "CD プレイヤー" and has the letter A in the ROM footer instead of J.
