The task of programming modifications was at hand
now. It was very important to understand the basic package
thoroughly, so that one could decide what to keep and
and what to change or add. IBM's package was well
designed in this respect. However, great care had to be
exercised when programs were being written simultaneously,
so that they all could be tied together as an integral system.
In a real-time system like ours, timing was a vital
factor and process interrupts had to be well thought out.
Off-line machine for program testing is a great asset under
the circumstances.