Starting Information; Record Advance Operation - IBM 3742 Reference Manual

STARTING INFORMATION
When the 3741 or 3742 power is turned on, the current
record, previous record, and hold buffers are filled with
blanks, and the program buffers are filled with N's. The
status line displays the machine-not-ready disk status (N),
the read index mode (X), program level 0, and current disk
address 00000. All other positions on the status line are
blank.
Closing the cover on the diskette that has been inserted
changes the disk status to wait (W). The volume label is
read, but it is not displayed, and the accessibility field in
the volume label is checked. If the accessibility field is not
blank, the disk cannot be processed, an A error is displayed,
and the 3741 or 3742 waits for the disk to be removed.
A write test is made; if not successful, ?? is displayed in
position 9 and 10 of the status line. If all previous tests
have been successful, sector 08 is read.
RECORD ADVANCE OPERATION
Use REC ADV during read index mode to read the next
record on the index track. The contents of the current
buffer are transferred to the previous record buffer unless
the current record buffer contains a deleted record. The
current disk address is incremented by one.
Pressing REC ADV during modify index mode writes the
record displayed in the current sector_
Pressing REC ADV during search mode starts one of the
search operations.
Pressing REC ADV during enter mode:
1. Transfers the record from the current record buffer
to the previous record buffer skipping all manual
fields and executing all automatic fields.
2. Writes the record on disk.
3.
4.
5.
Adds one to the end-of-data address and the current
disk address.
Sets the current record buffer to blank.
Moves the cursor to the first manual field position.
Using this key when at end of extent:
1.
Gives an E error.
2. Selects program level O.
3.
Selects read index mode.
4.
Displays the data set label.
Pressing this key in update mode (if data was entered):
1.
2.
3.
Transfers the contents of the current record buffer
to the previous record buffer.
Reads the next record into the current record buffer
and moves the cursor to the first manual position of
the record.
Replaces the old record on the disk with contents of
previous record buffer.
4. Increases the current disk address by
1.
If data has not been entered since the current record was
read, R EC ADV performs all of the preceding steps except
step 3. The mode changes to enter when record advancing
reaches the EOD address.
Pressing REC ADV during verify mode causes the station
to check for blanks in all remaining manual fields and
automatically verify all trailing auto fields. If no verifica-
tion error occurs, verification is completed. The present
record is moved into the previous record buffer. The
record in the hold buffer is then moved to the current buf-
fer and displayed. The current disk address increases by 1,
and the next record is read into the hold buffer.
If a verification error occurs, the cursor stops at the column
that caused the error. When verification is complete and
corrections to the record have been made, pressing REC
ADV causes the record to be written on the disk. If no
corrections are made, the record is not rewritten. If R EC
ADV is pressed when the cursor is in the first manual posi-
tion of a record, the current record is not verified, except
when a modification to the present record has been made.
An alternate method of record advance in enter mode can
be selected by pressing FUNCT SEL lower and then R. A
dash will appear in position 39 in the status line. The
record advance function in enter mode is changed so that
skip and duplicate fields that follow the position of the
cursor at the time of record advance are not executed. To
return the machine to the normal mode, press FUNCT SEL
lower and K. Inserting a disk or turning the power on will
also establish the normal mode.
Data Station Operating Information 17