Now finish the program. Add the two numbers and store the answer at 2002H.

The loading code from the previous step is already in the editor, so you only need the arithmetic and the store.

The one thing: Arithmetic always goes through A, and the carry flag is not an error — it is the ninth bit of an answer that outgrew the register.

What is being checked

• 2002H holds the sum
• The carry flag reflects whether the addition overflowed
• 2000H and 2001H still hold the original numbers
• The program reaches HLT
• You reach memory through HL, and not with LDA or STA

About the carry

FFH + 02H is 101H, which does not fit in eight bits. The accumulator keeps the low byte, 01H, and the carry flag records that a ninth bit was produced. The carry is not an error. It is the processor telling you the true answer was larger than one register can hold, and it is what makes multi-byte arithmetic possible later on.

You are not asked to do anything about the carry here. Just do not clear it: some instructions leave the flags alone and others do not, and the check will notice.