>The only real issue with this approach is that add and sub are really 9 bit
>outputs (8 bit result + carry/borrow) and most EPROMS only have 8 output
bits.
>So even though it's wasteful you may need to generate a carry/borrow EPROM
that
>simply outputs a single carry/borrow bit based on the input and ALU
function
>code.

However that same EPROM can be simultaneously generating a whole heap of
other flags, like Zero, Parity, half carry, and any other useful ones you
can think of.

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