IBM 1130 User Manual page 470

IBM Systems Area
The IBM Systems Area is present on all disk car-
tridges that have been built as systems disks (that is,
disk cartridges on which the Monitor system has
been loaded).
Section Subsections Page
60
10
I
20 01
This area consists of (1) a basic Monitor package
of 152 sectors, which must be present, (2) two
optional items, which may be removed:
FORTRAN compiler (88 sectors)
Assembler (32 sectors)
and (3) the Core Image Buffer (16 sectors), which
may be deleted from a satellite cartridge but must
be present on the master cartridge.