The 68000 doesn't need an A0 pin, because it uses 2 DS (LDS & UDS) signals - each being responsible for its byte on 16-bit data bus. [https://www.reddit.com/r/m68k/comments/1c53uli/how_does_the_the_23_bit_address_bus_on_the_64_pin/ Source]
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= Floating Point Unit =
Unlike the Intel 8086, the Motorola 68000 had no FPU co-processor. This feature debuted in 1984 with the 68881 chip, released exclusively for the 32-bit 68020 processor.
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