Epson 20 - Manual (Page 184)

Destructive Surface Analysis
Use this option to accurately locate any bad tracks on a hard disk,
and to flag any bad tracks that are not flagged.
This test operates by a complex process of writing, reading, and
verifying information on every track of the hard disk, except for
tracks that are already flagged as bad tracks. To start the test, press 3
and then
Enter. You see these messages:
Analyze Hard Disk
Read/Save/Write/Read/Restore/Read check for all
tracks...
Current cylinder is xxxx
As each track is checked, the cylinder number (xxxx) counts down to
zero. When the analysis is complete, the program displays a complete
report on the status of the disk, including a table of unflagged tracks
that produced write, read errors. For a hard disk with no unflagged
bad tracks, a display like this appears:
Analysis finished.
Count of tracks flagged bad
=
n
Count of tracks with write, read errors = 0
Count of good tracks
= n n n
No write, read error was detected.
No data was destroyed.
Press ENTER to return to the menu.
D-8 Physically Formatting a Hard Disk