According to one embodiment a computer system is disclosed. The method includes receiving first data compliant with a first protocol, and transmitting second data compliant with a second protocol, where the first protocol is downward compatible with the second protocol. The computer system can access the viable copy and replace the copy that includes the inappropriate content with the viable copy. The first transconductance circuitry is arranged to inject a transconductance current at a point along the first feedback resistance, and is configurable to vary the point along the first feedback resistance where the transconductance current is injected.