Epson 10020 - Manual (Page 205)

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.
WARNING
If any errors occur during this check, all data on the track
that produces the error is destroyed. For this reason, if you
think that an unflagged bad track is causing trouble, first run
option 4, Non-destructive surface analysis, to check the disk
surface.
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
nnn
As each track is checked, the cylinder number (nnn) 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, such
as the following:
Analysis finished.
Count of tracks flagged bad
= n
Count of tracks with write, read errors = n
Count of good tracks
= nnn
No write, read
error
was detected.
No data was destroyed.
Press ENTER to return to the menu.
E-10 Physically Formatting a Hard Disk