Epson 20 - Manual (Page 182)

Unconditional Format
Use this option to format your hard disk when you want to enter the
list of bad tracks before formatting begins. The main difference
between unconditional and conditional formatting is the way in
which bad tracks are identified. With the unconditional format, you
must enter the list of bad tracks before formatting begins.
To start the Unconditional format routine, press 2 and then Enter.
You are first given the option to change the interleave factor for
formatting from the default value of one. Only do this if the
documentation with your hard disk recommends a different value.
You see this prompt:
Do you want default interleave of 1 (Y/N)?
To accept the default, press Y and Enter. To change the value, press
N and Enter. You see this prompt:
Enter interleave factor
(l-n):
where n is equal to the maximum sector number. For the ST-506 hard
disk,
n
is 16; for the ESDI hard disk, n is either 33 or 35. Type the
recommended value and press Enter. The next screen allows you to
edit the table of bad tracks:
Bad Track Table
Cylinder Head Cylinder Head Cylinder Head Cylinder Head Cylinder Head
Move highlighted area to desired track with cursor keys.
A = Add track, C = Change track, D = Delete track, F = Finish editing
Enter command letter :
D-6 Physically Formatting a Hard Disk