When writing commands to a file or to the control memory, the following guidelines should be observed:
1. Commands other than NOP can reside every four steps. Micro code should be the same for all four steps except for I/O Groups Control direction and Operation Code. The Operation Code should be encoded only in the fourth step.
2. The direction can be changed at each step.
3. Control memory and output memory must be written to all boards, Master and Slave.