▁separated ▁controller ▁and ▁disk ▁system ▁like ▁that ▁of ▁the ▁ST 5 0 6 ▁interface , ▁sometimes ▁the ▁problem ▁can ▁be ▁resolved ▁by ▁connecting ▁the ▁disk ▁drive , ▁containing ▁the ▁actual ▁( per haps ▁very ▁important ) ▁data , ▁to ▁another ▁compatible ▁controller . ▁Furthermore , ▁an ▁ST 5 0 6 ▁style ▁interface ▁makes ▁it ▁possible ▁and ▁easy ▁not ▁only ▁to ▁replace ▁the ▁controller ▁without ▁throwing ▁away ▁the ▁data , ▁but ▁to ▁get ▁access ▁to ▁the ▁analog ▁data ▁signals ▁from ▁the ▁disk ▁drive ▁and ▁process ▁them ▁through ▁a ▁special ▁data ▁recovery ▁system ▁that ▁may ▁be ▁able ▁to ▁re construct ▁data ▁that ▁a ▁normal ▁controller ▁cannot ▁read . ▁Such ▁data ▁recovery ▁techniques ▁are ▁much ▁more ▁difficult ▁to ▁execute ▁on ▁integrated ▁drives , ▁because ▁the ▁needed ▁analog ▁signals ▁from ▁the ▁disk ▁are ▁not ▁available ▁at ▁a ▁standard ▁interface ▁and ▁the ▁internal ▁data ▁recording ▁method , ▁sector ▁format , ▁and ▁disk ▁organization ▁of ▁nearly ▁every ▁integrated ▁drive ▁model ▁is ▁different ▁and ▁secret . ▁ ▁Comp at ible ▁systems ▁and ▁develop ments ▁▁ ▁Many ▁other ▁companies ▁quickly ▁introduced ▁drives ▁using ▁the ▁same ▁connect ors ▁and ▁signals , ▁creating ▁a ▁hard ▁drive ▁standard ▁based ▁on ▁the ▁ST 5 0 6 . ▁IBM ▁chose ▁to ▁use ▁it , ▁acqu iring ▁adapter ▁cards ▁for ▁the ▁PC / XT ▁from ▁X eb ec ▁and ▁for ▁the ▁PC / AT ▁from ▁Western ▁Digital . ▁As ▁a ▁consequence ▁of ▁IBM ' s ▁end ors ement , ▁most ▁of ▁the ▁drives ▁in ▁the ▁ 1 9 8 0 s ▁were ▁based ▁on ▁the ▁ST 5