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IN xxFE addresses used in games

Mr XMr X
in Games
Apart from
00FE and 7FFE, BFFE, DFFE, EFFE, F7FE, FBFE, FDFE, FEFE
did game writers commonly use other 16-bit addresses to read the keyboard?

0FFE or F0FE perhaps? Thanks in advance for any replies.

Comments

  • Alcoholics AnonymousAlcoholics Anonymous
    edited February 2016
    They have to. The upper 8 bits determines which key row is activated. The ones they care about depends on what keys they are scanning. 0x0ffe and 0xf0fe are going to be very uncommon because those activate four key rows at the same time (why would you do that?) whereas most of the others you listed are only activating one (a reset bit indicates activated row). 0x00fe is special because it activates all rows and will be used to find out if any key is pressed.
    Post edited by Alcoholics Anonymous on
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