The FeedBack Modifier FBM is a table with four 16-bit values in our demo. After the completion of a 32-bit random number this table is reorganized. We replace the fourth value with the third, the third with the second and the second with the first. The first FBM is newly created.

To generate the new FBM we take the lower 16 bits from the last generated 32-bit random number and execute an XOR bit-wise with the next Basic Modifier BM. The XOR-operation (Exclusive-OR) means that the bit-position with only one "1" on the last random number and the BM-value will result in a "1". If both bit-positions are zeros or ones, the result will be a "zero". From the four possible cases 0/0, 1/1, 0/1 and 1/0 we get in two cases a "zero" and in two cases a "one". If we have on the two operands random values with 50 percent probability for a "0" or a "1" at each bit-position, we can produce a different new random value with the XOR-operator as the probability for every bit-position is also 50 percent for a "0" and 50 percent for a "1".

In the demo we show this effect by superposing both values in the third field. If a clear "0" or a clear "1" appears on a bit-position, we see that we have 0/0 or 1/1, resulting in a "0" bit at this position. If we see a combination of a zero and a one, we have either 0/1 or 1/0, and the result will be "1".

By using 16 bits from the last generated random number as one operand for the XOR operator, we insert an indirect feedback into the generation of the random numbers.