Epson 20 - Manual (Page 185)

If the program finds one bad track that is not flagged, the summary
would show one track with a write, read error. The report is then
followed by a table like this:
Write, Read Error Tracks
Cylinder Head Cylinder Head Cylinder Head Cylinder Head
237 2
Confirm to register the tracks in the Write, Read Error
Track Table as bad tracks.
Do you want to register the error tracks as bad tracks (Y/N)?
To flag the error tracks as bad, press Y and Enter. You then see a list
of the tracks as they are flagged and then these messages:
Flagging bad tracks...
Cylinder is 237, head is 2
Press ENTER to return to the menu.
Press Enter to return to the HARD DISK FORMAT MENU.
Non-destructive Surface Analysis
The Non-destructive surface analysis is slightly simpler than the
Destructive surface analysis described in the previous section. This
option does not destroy any data, and can safely be used to check the
condition of your hard disk drives. However, this test does not flag
any bad tracks that are detected.
To start the test, press 4 and then Enter. You see these messages:
Analyze Hard Disk
Read/Verify check for all tracks...
Current cylinder is xxxx
As each track is checked, the current cylinder is displayed. The
cylinder number counts down to zero as the disk is checked.
Physically
Formatting a Hard
Disk D-9