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ADCA MEM ;A+MEM+Carry
ADCB MEM ;B+MEM+Carry
- If the carry flag is set, one is added to the result of the addition.
The carry flag would likely be affected (set or cleared) by a previous addition.
Using the add with carry instructions allows multibyte additions of any byte length.
When adding byte-sized numbers the carry flag is set by a carry out of bit 7. When adding 16-bit quantities (addd) the carry flag is set by a carry out of bit 15.
The following addition generates a carry and a half carry.
The following addition generates a carry but not generate half carry.
The following addition does not generate a carry but generate a half carry.