English Amiga Board - View Single Post - Need some help with setting up Trifecta 500 LX emu

mark_k · 26 January 2020, 21:18

Refer to the devices/hardblocks.i include file.

The RigidDiskBlock is in sector 1 = byte offset $200.
At offset $1C in that is the PartitionList field which contains 5. That means the first PartitionBlock is in sector 5.

Sector 5 is at offset $A00. In the PartitionBlock at offset $80 is a DosEnvec structure.
In each PartitionBlock you have values for Surfaces at offset $8C, BlocksPerTrack at $94, Reserved at $98, LowCyl at $A4, HighCyl at $A8. From those you can work out the byte offset & length of each partition.

26 January 2020, 21:18	#10
mark_k Registered User Join Date: Aug 2004 Location: Posts: 3,344	Refer to the devices/hardblocks.i include file. The RigidDiskBlock is in sector 1 = byte offset $200. At offset $1C in that is the PartitionList field which contains 5. That means the first PartitionBlock is in sector 5. Sector 5 is at offset $A00. In the PartitionBlock at offset $80 is a DosEnvec structure. In each PartitionBlock you have values for Surfaces at offset $8C, BlocksPerTrack at $94, Reserved at $98, LowCyl at $A4, HighCyl at $A8. From those you can work out the byte offset & length of each partition.