Initialization Procedure; Disk Checking - IBM 3742 Reference Manual

INITIALIZATION PROCEDURE
The disk to be initialized must be in the index track. On the
3742 be sure the second disk drive does not contain a disk.
To initialize the disk, do the following:
1. Load disk.
2. Press FUNCT SEL lower, then DELETE.
3. Key the following data:
Volume I D in positions 1-6
Sector sequence in positions 7-8 (normally left blank)
Bad track 1 in positions 9-10
Bad track 2 in positions 11-12
Blank in positions 13-14
Blank for record length of 080 in position 15
L for record length of 128 in position 15
4.
Press FUNCT SEL lower, then press the 2 key.
Any or all of the data in step 3 may be left blank. If the
volume I D is left blank, the volume I D will be written as a
blank field. If the sector sequence is left blank, the se-
quence of sectors will be in numeric order (1, 2, 3, .... 25,
26). If no bad tracks are listed, the initialization operations
will scan the disk to find any defective tracks marked with
the bad track code. When one or two bad tracks are speci-
fied, initialization operations do not check for the bad
track code and will try to initial ize all other tracks.
When the initialization process is complete, the disk is
positioned at track 00 and the label in sector 08 is displayed
unless errors were encountered. In case of errors, the
following will be displayed:
• Bad tracks that have been marked with the bad track
code are displayed in the first data line. Positions 9 and
10 show the first bad track; 11 and 12 show the second
bad track.
• Tracks that showed errors when checked are shown in
data line 2 beginning in cursor position 4
t.
Each track
shown is written with three characters followed by a
space. The first two characters indicate the track num-
ber and the third character indicates the type of error
encou ntered:
I
C
Missing I D field
CRC error
S Deleted record
Only 10 tracks with errors can be displayed; the first error
encountered in a track is displayed.
If errors are displayed after initialization, the initialization
was not successful. The disk should be removed to clear
errors and initialization tried again until. a successful opera-
tion occurs. If particular tracks show persistent errors in
successive retries, those tracks should be considered defec-
tive. Initialization can be retried by specifying those tracks
in the keyed data of step 3. Since the maximum number of
bad tracks that can be specified is 2, disks with persistent
errors in more than two tracks cannot be used.
DISK CHECKING
The initialization feature provides a means of checking a
disk for tracks marked with the bad track code and for
tracks exhibiting errors. The procedure for checking is as
follows:
1. Load the disk.
2.
Press FUNCT SEL lower and DELETE REC
3.
Press FUNCT SEL lower
4. Press the I character
At the end of the scan, a report is posted on the display in
the same format as used for reporting errors after initial-
izing. If errors are reported, the disk should be checked re-
petitively and only tracks that show persistent errors in re-
peated operations should be considered bad.
Disk Initialization 41