This is the ROM card for the Extended Controller, giving the box EC personality and algorithms. Revision 9 or better is required for LCN compatibility.

The latest version of the EC ROM card prior to the introduction of the Universal Controller is the 30751044-009, which has a potential flaw in its address decode circuit (depending on its revision). The 30751044-004 and 30751044-007 ROM cards are not susceptible to this flaw.

This EC ROM card must have issue 9 or better for LCN / Hiway Gateway compatibility.