Data storage and retrieval using perpendicular media and magnetoresistive read transducer

We have investigated magnetic recording on multilayer perpendicular media using a conventional peak detect channel and a commercial magnetoresistive recording head. A finite impulse response filter was used to equalize the impulse response from perpendicular media into a unipolar pulse. Equalized pulses had a PW/sub 50/ of 174 nm and a D/sub 50/ of 131 kfei. Without write precompensation, a linear density of 204 kbits per inch (kbpi) with a 3.3 ns error window margin and a data transfer rate of 75 Mbit/s was measured with an error rate of 4/spl times/10/sup -7/. The signal waveform was stable and had good up-down amplitude symmetry.