I couldn't find a topic for that, so I create a new thread to share my codes.
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Secret Of Mana
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Hero:
E1D063: Fist increases level after next use
E1D163: Sword increases level after next use
E1D263: Axe increases level after next use
E1D363: Spear increases level after next use
E1D463: Whip increases level after next use
E1D563: Bow increases level after next use
E1D663: Boomerang increases level after next use
E1D763: Javelin increases level after next use
Sprite:
E58663: magic points always at 99
E5D063: Fist increases level after next use
E5D163: Sword increases level after next use
E5D263: Axe increases level after next use
E5D363: Spear increases level after next use
E5D463: Whip increases level after next use
E5D563: Bow increases level after next use
E5D663: Boomerang increases level after next use
E5D763: Javelin increases level after next use
E5D863: Gnome increases level after next use
E5D963: Undine increases level after next use
E5DA63: Salamando increases level after next use
E5DB63: Sylphid increases level after next use
E5DC63: Luna increases level after next use
E5DD63:
E5DE63: Shade increases level after next use
E5DF63:
Girl:
E38663: magic points always at 99
E3D063: Fist increases level after next use
E3D163: Sword increases level after next use
E3D263: Axe increases level after next use
E3D363: Spear increases level after next use
E3D463: Whip increases level after next use
E3D563: Bow increases level after next use
E3D663: Boomerang increases level after next use
E3D763: Javelin increases level after next use
E3D863: Gnome increases level after next use
E3D963: Undine increases level after next use
E3DA63: Salamando increases level after next use
E3DB63: Sylphid increases level after next use
E3DC63: Luna increases level after next use
E3DD63:
E3DE63:
E3DF63: Lumina increases level after next use
The 63s stand for a value of 99.
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Secret of Evermore
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004EB3FF: boy health
004F61FF: dog health
000A49FF: boy experience
000A93FF: dog experience
000AC6FF: money
The FFs stand for a value of 255.
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Seiken Densetsu 3
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01EDF2xx: health at xx
01EDFFxx: experience at xx
002C24xx: money at xx
Replace xx by FF to get 255. If you want more than xx, you'll have to modify the high byte as well.
E.g. for a health at 256, you'll need to have 01EDF200 and 01EDF301 (correct me if I'm wrong).