APPENDIX B

 SUBPROGRAM DESCRIPTIONS



 The subroutines making up the GENIE system are arranged in a

hierarchy. The highest level of the hierarchy is level 0, which is the

GENIE executive routine described in Chapter 5. The hierarchy is set

up so that routines on any level can only be called by routines on a

higher level and can only call routines on a lower level. Levels 1

through 6 will be discussed here. Level 6 routines, being on the

lowest level, call no other routines. Level 1 routines are the routines

called only by the GENIE executive routine. Table B-1 contains a list

of all subprograms belonging to each level. Reference to a subprogram

will be by name, followed by the level and number, in parentheses. For

example, the subprogram J1TEAR will be referred to as J1TEAR (5.6).

Preceding the discussion of each of the subprograms is a list of all

of the subprograms referenced by (that is, called by) that subprogram.

Because none of the common areas (except MEMORY) are checked for

available space before data is stored in them, a system of special "stop

codes" is used to indicate data storage problems. This philosophy was

adopted to eliminate constant checking for available space. It appears

to be a good policy, as problems with data storage are rarely encoun-

tered.