Dragster : The A1020 is a 40 track drive (the Amigaos system automounts all 80 track drives, either 3"1/2 or 5"1/4). So you will have to write a mountlist like in earlier days of WB1.2/1.3 ! I'll suggest you simply check and adapt the mountlist file in Devs: directory on a WB1.3 (or 1.2) disk...
Mountlist sample (1.3 style)
/* Mount a 5.25" disk drive to be mounted as DF1: */
DF1: Device = trackdisk.device
Unit = 1 /* first external unit */
Flags = 1 /* important ! */
Surfaces = 2
BlocksPerTrack = 11
Reserved = 2
Interleave = 0
LowCyl = 0 ; HighCyl = 39
Buffers = 20
BufMemType = 1 /* or 3 if you run OS 1.x */
#
Dosdriver form (2.x/3.x style)
Device = trackdisk.device
Unit = 1 /* first external unit */
Flags = 1 /* important ! */
Surfaces = 2
BlocksPerTrack = 11
Reserved = 2
Interleave = 0
LowCyl = 0 ; HighCyl = 39
Buffers = 20
BufMemType = 1 /* or 3 if you run OS 1.x */
Simply save it as DF1 (or A1020 if you prefer) in your Dosdrivers directory (generally in Sys:storage). Open a shell and try mount df1: (or A1020:) !
According to (french programmer) Etienne Vogt, the important thing is to set Flags=1 (tells the trackdisk.device that you really want to mount a 40 track drive, else it will ignore it)
You could also try to mount 360 Kb MS-DOS disks with something like (to save as PC1 dosdriver or A1020PC for example):
FileSystem = L:CrossDOSFileSystem
Device = mfm.device
Unit = 1 /* first external unit */
Flags = 1
Surfaces = 2
BlocksPerTrack = 9
Reserved = 1
Interleave = 0
LowCyl = 0
HighCyl = 39
Buffers = 20
BufMemType = 1 /* or 3 if you run OS 1.x */
StackSize = 600
Priority = 5
BufMemType = 0
StackSize = 600
Priority = 5
GlobVec = -1
DosType = 0x4D534400
Mount = 1
Another thing : your A1020 had an external power ?