[symbols]
$0000=buf0CommandStatus
$0001=buf1CommandStatus
$0002=buf2CommandStatus
$0003=buf3CommandStatus
$0004=buf4CommandStatus
;$0005=unused
$0006=buf0TrackSectorLo
$0007=buf0TrackSectorHi
$0008=buf1TrackSectorLo
$0009=buf1TrackSectorHi
$000A=buf2TrackSectorLo
$000B=buf2TrackSectorHi
$000C=buf3TrackSectorLo
$000D=buf3TrackSectorHi
$000E=buf4TrackSectorLo
$000F=buf4TrackSectorHi
; $0010=unused
; $0011=unused
$0012=unit0ExpectedSectorHeaderLo
$0013=unit0ExpectedSectorHeaderHi
;$0014=unused
;$0015=unused
$0016=headerIDLo
$0017=headerIDHi
$0018=trackSectorLo
$0019=trackSectorHi
$001A=checksum
;$001B=unused
$001C=diskChangeIndicator
;$001D=unused
$001E=previousDiskChangeIndicator4
;$001F=unused
$0020=unit0InternalCommand
;$0021=
$0022=unit0TrackNumber
$0023=communicationSpeed
$0024=gcrHeader
;..$002B
;$002C=unused
$002E=curPosPLo
$002F=curPosPHi
$0030=bufPLo
$0031=bufPHi
$0032=trackSectorPLo
$0033=trackSectorPHi
$0034=GCRByteCounter
;$0035=unused
$0036=byteCounter2
;$0037=unused
$0038=signature
$0039=expectedSectorHeaderSignature
$003D=unitNumber
$003E=previousUnitNumber
$003F=bufNumber
$0040=trackNumber
$0041=seekNeededBufNumber
$0042=seekTrackCount
$0043=sectorCountOnTrack
$0044=dataDensity
$0045=bufferCommandRegister
$0047=expectedDataBlockHeaderSignature
;...