Zenith Z-100 Series, Руководство пользователя

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Page 16
WINCHESTER SUPPLEMENT
The PREP Utility
Now the disk will be tested seven times. Each test is known
as a "pass." The seven passes of the test that are now per-
formed are conducted to check the integrity of the disk's stor-
age capacility. During each pass, PREP will "write" a pre-
determined code in each sector (the LED drive access light
will flicker) and then will "read" back that code to verify that
it remained correct (the LED drive access light will appear
to be constantly on). PREP will keep you informed of its prog-
ress by displaying the message:
Media test in progress. Pass n
where n represents the current pass number. This phase of
PREP takes about an hour and a half because of the large
number of sectors on the Winchester disk system.
PREP uses a diff erent code on each pass it makes through
the test. If PREP finds questionable areas on the disk, it stores
the address where the error occurred, and later places these
addresses into a bad sector table.
When PREP has fi nished the seven passes, two "superblocks"
and two bad sector tables are recorded on the disk. While
it is doing this, you will see:
Initi a l i z ing the disk...completed
A "superblock" is a portion of the disk surface (on cylinder
0) that is used to keep track of the disk "partition" names,
the operating system name assigned to each partition, a flag
that is used to show whether the partition has been formatted
or not, and a pointer (or number) for the first sector of that
partition. The superblock is recorded twice on the Winchester
disk. Each copy is written with a different disk head so that
the copies are physically isolated from each other. If some-
thing occurs to damage one copy of the superblock, the other
may remain usable.