Help System (web edition)

The current record is deleted from the data file by alt-F10 key.
An empty record is inserted after the current record by the alt-F9 key.

When records are inserted and deleted (or moved by alt-F4), the FILE
SHOW operation does not change the contents of the data file immediately,
but creates a special indicator vector for this purpose. If n is the
number of records, an extra space of 4*(n+1000) bytes is needed in the CPU.
This space will be automatically reserved by FILE SHOW. In very large
data files of, say more than 40000 records, allocation of the extra
space may be impossible. In that case FILE SHOW will give a message
and operations like FILE EDIT or FILE COPY should be used for the task.
The maximum number of new records to be inserted between the old ones
is 1000.
When records have been inserted and deleted in the preceding manner,
and FILE SHOW is terminated (by F8), the pertinent information will be
copied from the current data file to a new one (SURVO.XXX) on the
same path on the disk. Then the original file is deleted and SURVO.XXX
renamed with the true name.

Please, note that the restrictions above do not apply to new records typed
at the end of the data. There are no relevant limits for the number of
old and new records.
  S = More information on FILE SHOW