Trivia: the article says the Z80 had "full compatibility" with the 8080, but that isn't true. Here and there programs failed because of it. In the 8080, most

Trivia: the article says the Z80 had "full compatibility" with the 8080, but that isn't true. Here and there programs failed because of it. In the 8080, most ALU operations set the "P" (parity) flag to indicate if the result had an even or odd number of 1 bits. On the Z80, that flag would be set the same way for logical operations (AND, OR, XOR), but for ADD/SUB operations it was used as an overflow flag -- not carry out, but it indicated that the 2s-complement result wasn't able to accurately represent the result. There were also some changes in the way the half-carry (nibble carry out) flag was handled in some instructions too.