The 74LS189 is a 4 bit RAM IC. The datasheet specifies that the output of the chip is inverted. Thus, if you put
1011 into address 1, when you read back address 1 it will output
Most of the time, it makes sense why certain chips have certain inputs/outputs inverted, but for a RAM chip, I cannot see any reason that you would want to get any data out other than the data you put in.
Is there some practical reason that the outputs are inverted?