For example, to add two 16-bit numbers on my 8 bit machine, I add the low bytes together, then the high bytes together, and then add the carry flag to the high byte of the output.
This strategy falls apart when dealing with twos complement signed numbers.
How do I handle adding two 16-bit signed numbers, when my ALU can only process 8 bits?
This strategy falls apart when dealing with twos complement signed numbersPlease describe, in your question, how this falls apart. $\endgroup$