IBM 1130 User Manual page 482

Format of Material on the Disk
Essential to the understanding of DUP is a basic
knowledge of the various formats used in the storing
of programs and data on the disk.
Although DUP gives you many format options,
this section discusses only those that apply to the
average user, writing a typical FORTRAN program.
Users with unusual combinations (for example, a
data file in DCI format) will have exercised this
option with a specific purpose
in
mind and will be
well aware of the details involved.
Data Files
Under normal circumstances, data files are always
stored on the disk in the Disk Data Format (DDF).
Programs and Subprograms
Under normal circumstances, programs and sub-
programs will be stored on the disk in one of two
formats:
Disk System Format (DSF)
Disk Core Image Format (DCI)
Section Subsections Page
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The main difference between the two lies in what is
stored, rather than how it is stored.
A program in DCI format cons ists of a complete,
self-sufficient core load or program package -- the
mainline program, plus all the subroutines it re-
quires. The entire package is in absolute form;
. that is, all addresses are actual core storage lo-
cations rather than relative locations. Subprograms
cannot be in DCI format.
On the other hand, an item in DSF consists of that
item and only that item. Nothing else is included
with it. It may be:
• A program or a subprogram
• Absolute or relocatable (but usually relocatable)
• In either WS or UA (but not in the FX)
As would be expected, a program occupies more
space on the disk in DCI form than
it
would in DSF,
since it includes more material. However, it may
be loaded into core storage (when called by an
XEQ card) much faster, since the Core Load Builder
need not assemble all the necessary subroutines and
calculate actual core storage addresses.