Transforming engine maps for ROMBIC

ROMBIC is a ROM-based digital ignition controller which generates a spark advance as a two-dimensional function of RPM and engine load, or vacuum. Its ROM contains time domain information related to the advance; this enables the controller to have a relatively simple architecture, and to operate in the time domain. The computation of the ROM contents is based upon engineering data for an engine, families of curves of spark advance vs. RPM with vacuum as a parameter. Computer programs which map the angle-degree domain data into the time domain have been developed. The algorithms employed in these programs are outlined.