What is a Cassie keyboard?
The keyboard in question looks like this:
http://www.farclip.com/hardware/images/Apple_Keyboard-M0116.jpg
All that I can say about the microcontroller at this point is that it doesn't have the quartz(?) window, so the ROM definitely isn't UV erasable. Though, to my limited knowledge, that doesn't necessarily mean that it has a mask ROM either.
The keyboard in question looks like this:
http://www.farclip.com/hardware/images/Apple_Keyboard-M0116.jpg
All that I can say about the microcontroller at this point is that it doesn't have the quartz(?) window, so the ROM definitely isn't UV erasable. Though, to my limited knowledge, that doesn't necessarily mean that it has a mask ROM either.