8/10 modulation codes for digital magnetic recording

It is difficult to record DC and low-frequency signals with the magnetic recording method. Furthermore, in high-density magnetic recording, the signal-to-noise ratio and the high-frequency output level are low and low-frequency crosstalk noise from the adjacent tracks is relatively high. A modulation code for high-density digital magnetic recording must have a large Tw and a DC-free characteristic. When we developed the R-DAT system, we developed two run-length limited 8/10 conversion rate modulation codes for use with the R-DAT. This paper discusses various possible modulation codes and confirms the superiority of one particular 8/10 modulation code.