KEY0 info

This commit is contained in:
Lior Halphon 2021-04-13 23:34:49 +03:00
parent 6f0b640702
commit c1509b6339

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@ -74,6 +74,7 @@ The values of memory-mapped registers should be written 'as-is' to memory as if
* Unused registers have Don't-Care values which should be ignored
* Unused register bits have Don't-Care values which should be ignored
* If the model is CGB or newer, the value of KEY0 (FF4C) must be valid as it determines DMG mode
* Bit 2 determines DMG mode. A value of 0x04 usually denotes DMG mode, while a value of `0x80` usually denotes CGB mode.
* Sprite priority is derived from KEY0 (FF4C) instead of OPRI (FF6C) because OPRI can be modified after booting, but only the value of OPRI during boot ROM execution takes effect
* If a register doesn't exist on the emulated model (For example, KEY0 (FF4C) on a DMG), its value should be ignored.
* BANK (FF50) should be 0 if the boot ROM is still mapped, and 1 otherwise, and must be valid.