MDFS::Info.Comp.BBC.Hardware.IDE.Specs/htm Search  

BBC IDE Interface Specification

The IDE interface is mapped into memory at &FC40-&FC4F.
AddressWriteRead
&FC40Data Low Byte
&FC41Special FeaturesError
&FC42Sector Count
&FC43Sector or LBA b0-b7
&FC44Cylinder b0-b7 or LBA b8-b15
&FC45Cylinder b8-b15 or LBA b16-b24
&FC46b6=HCS/LBA, b4=device, b3-b0=head or LBA b25-28
&FC47CommandStatus
&FC48Data High Byte
&FC49-
&FC4A-
&FC4B-
&FC4C-
&FC4D-
&FC4E-
&FC4F-
HCS is head:cylinder:sector addressing. LBA is logical block addressing.
Authored by J.G.Harston
Last update: 30-Jun-2004