An algorithm for “8275 Programmable CRT Controller” timing

An algorithm is developed to determine the `8275 Programmable CRT Controller' timing parameters for a given CRT monitor requirements and the desired display format. This algorithm has been implemented in BASIC language and executed on the TRS-80 computer. There may not always exist a set of 8275 parameters satisfying simultaneously the monitor and display format requirements. This is allowed for by leaving the choice of modifications in requirements to the programmer. When the choice of modification in requirements works out to be obvious, program execution continues after indicating to the programmer the decision taken. The flow chart and the program are shown.