Found format "ibm" PLL Parameters: period_adj=5% phase_adj=60% T0.0-7.1: IBM-MFM DD (16 256-byte sectors, 4096 bytes) T8.0: IBM-MFM DD (15 256-byte sectors, 3840 bytes) T8.1-79.1: IBM-MFM DD (16 256-byte sectors, 4096 bytes) T80.0-83.1: Unformatted
