Alright, let's get this straight. I saw on the official gameboy documents that the cpu core inside of the gameboy is clocked at 1.05 mhz and they say that that's the "system operating frequency". But what makes me question this is that someone else stated that Nintendo was only measuring in machine cycles other than clock cycles, which makes no sense because another dev stated they worked on tomb raider for the gbc and that the internal cpu inside the soc is in fact clocked at 1.05mhz he also stated some kind of method on verifying the clock speed. What I believe is that the gameboy cpu (soc with all of the internals such as ppu the audio mixer etc.) Has a master clock speed of 4.1943mhz, and the cpu core within the soc is clocked at 1.05mhz. I believe this because systems such as the game gear have a master crystal clocked at something like 50mhz or something and that is sure let not the clock rate of the cpu. That is the master clock for all of the logic chips, and if your talking about the 1chip version that will be the master clock for the soc. So, evidence leads me towards believing that the 4.1943mhz clock is the master clock rate of the gb soc, not the cpu. Please correct me if your sure I'm wrong, or give some input on this topic.