Deleted Records; Mode Considerations For Deleted Records; Ce Mode - IBM 3742 Reference Manual

DELETED RECORDS
Every nondeleted record on a disk has a data address mark
immediately preceding the data characters; this address
mark is not displayed. For a deleted record, this address
mark is changed to a control address mark which identifies
the record as being deleted. Deleted records normally have
a D written in the first data position. To delete a record
and preserve the data in the first position, press FUNCT
SEL lower and then simultaneously press DELETE REC
and NUM SH I FT. To delete records on the index track,
modify index mode must be used.
Mode Considerations for Deleted Records
Enter Mode: Pressing DELETE REC during enter mode
blanks the current record buffer and positions the cursor
at the first manual position. The previous record buffer is
unchanged.
Update Mode: If, during update mode selection from the
index track, a deleted record is read into the current record
buffer, the previous record buffer will contain the same
deleted record. If a deleted record is in the current record
buffer when a record advance occurs during update mode,
the record is not transferred to the previous record buffer.
If a deleted record is encountered during record backspac-
ing, the previous record buffer is not changed.
When deleting a record, the first character is changed to a
D in the current record buffer, and the remainder of the
content in the current record buffer remains unchanged. A
beep occurs when the delete function is complete. The cur-
sor is positioned at the first manual position displaying the
deleted record.
Verify Mode: When selecting verify mode from the index
track, the first nondeleted record in the data set is read
into the current record buffer.
If verify mode is selected from update or verify mode and
the currently displayed record is a deleted one, the next
nondeleted record is read into the current record buffer. In
either case, the previous record buffer is blanked.
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When a record advance occurs and a deleted record is in the
hold buffer (next sequential record is deleted), the next
nondeleted record is read into the current record buffer by-
passing all deleted records encountered. If a deleted record
is encountered during record backspacing, the deleted
record is read into the current record buffer with the pre-
vious record buffer unchanged.
When deleting a record, the contents of the previous
record buffer remains unchanged and a record advance
function is performed.
Search Mode: Pressing DE LETE REC during search mode
blanks the current record buffer and positions the cursor
at the first manual position. The previous record buffer
and the record at current disk address are unchanged. If
the search operation terminates on a deleted record, both
the current and previous record buffers contain the deleted
record.
CE MODE
CE mode is used by the customer engi neer when testi ng or
troubleshooting the equipment. This manual does not des-
cribe how this mode works or how it is used but merely
points out how it is entered and how to get out of the
mode.
Pressing FUNCT SEL lower followed by the" key puts the
machine in the CE mode. The status line displays CER in
positions 38, 39 and 40.
Pressing RESET several times returns the machine to the
index mode with the label from sector 08 displayed. After
the machine leaves CE mode, the program buffers of the
3741 may be changed and therefore should be checked.
The EOD and verify mark of the data set label that was
current when the CE mode was entered may be in error and
should be checked.
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