General Description
The UM8398 is a VLSI  Floppy Disk Controller (FDC) chip, which contains the circuitry and control functions for interfacing a processor with up to 2 floppy disk drives.

FEATUREs
◾ IMB PC XT/AT drive system compatible
◾ Support 2 drives (MS-DOS support)
◾ 1.2M/360K/720K format selectable
◾ IBM PC drive system address decoder
◾ Only 3 components for the drive
◾ Internal wite precompensation circuit; precompensation
   values: 250-125 ns
◾ internal date separator circuit 
◾ Supports to control 8", 51/4", 31/2" drives