IBM 1130 User Manual page 90

Section
Subsections Page
15 10
I
60 01
Your Backup Requirements
Whenever you work with files containing important
data (payroll, accounting, etc.), you should not
ignore the possibility of accidental destruction of
this information. Many accidents can befall card
decks ~ card jams in the reader, floods, spilt
coffee, misplacement, etc. Because you can re-
cover from many of these accidents by patching torn
cards, duplicating watersoaked cards, etc., it is
not too common to find duplicate sets of master
card files maintained.
Data files kept on the disk cartridge are subject
to a similar list of accidents, but with a difference:
it is often impossible to reconstruct the data after
an accident, unless you have planned for just such
an occurrence.
Because of the need for preplanning, the matter
of backup may be considered a disadvantage for the
disk file.
In
actuality, it may be on the plus Side,
since it forces duplicate files.