Because of limited chip area , complex operations like multiplication, division, etc are not available, in earlier processors like 8085.

The operations performed on binary 2's complement data.

The five flag bits give the status of the microprocessor after an ALU operation.

The carry (C) flag bit indicates whether there is any overflow from the MSB.

The parity (P) flag bit is set if the parity of the accumulater is even.

The Auxiliary Carry (AC) flag bit indicates overflow out of bit –3 ( lower nibble) in the same manner, as the C-flag indicates the overflow out of the bit-7.

The Zero (Z) flag bit is set if the content of the accumulator after any ALU operations is zero.

The Sign(S) flag bit is set to the condition of bit-7 of the accumulator as per the sign of the contents of the accumulator(positive or negative ).