|'''#FD09''' || Error Register || Features Register/''(Write Precomp Reg.)''
|-
|'''#FD0A''' || Sector Count (0=256) || Sector Count(0=256)
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|'''#FD0B''' || Sector Number (for CHS or LBA bits 0-7) || Sector Number (for CHS or LBA bits 0-7)
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|'''#FD0C''' || Cylinder Low (for CHS or LBA bits 8-15) || Cylinder Low (for CHS or LBA bits 8-15)
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|'''#FD0D''' || Cylinder High (for CHS or LBA bits 16-23) || Cylinder High (for CHS or LBA bits 16-23)
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|'''#FD0E''' || Device/Head Register (Bit 6=0 CHS, Bit 6=0 LBA) (Bit 4 = 0 Master, Bit 4 = 1 Slave) (Bits 3..0 Head for CHS or LBA bits 24-27) || (Bit 6=0 CHS, Bit 6=0 LBA) (Bit 4 = 0 Master, Bit 4 = 1 Slave) Device/Head Register (Bits 3..0 Head for CHS or LBA bits 24-27)
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|'''#FD0F''' || Status Register || Command Register