A programmable controller (PC) which can control general sequential process is developed. The Z-8OA microprocessor-based PC includes hardwares such as programming device, input/output modules, timer/counter modules, and power-failure recovery module which for soft-ware, initialization program, monitor program, execution program, and power-failure recovery program are developed. In particular, the PC is designed in such a way that a timer can be used several times in different time intervals and a skip capability is incorporated in the user program to reduce scan time.