PURPOSE: To obtain a travelling distance meter for a car which can sufficiently resist to be put to practical use by using an EPROM or a PROM as a storage means and inverting the contents of a bit successively at every travelling of the car by a fixed distance to store the total travelling distance.
CONSTITUTION: When a key switch is turned on, a microcomputer 2 starts arithmetic processing, retrieves the position (pointer) of "1" adjacent to "0" on the basis of data stored in the EPROM 4, finds out the total travelling distance from the number of "0" bits and displays the total travelling distance on a display device 5. Subsequently, the microcomputer 2 integrates distance data on the basis of distance pulses from a distance sensor 1, and when the integrated result reaches 1km, "0" is written in the bit on the position of the pointer of the EPROM 4, changes the pointer to the adjacent high-order bit and updates the display of the total travelling distance by the updated pointer. Thus, the total travelling distance can be stored under nonvolatile state in addition to the property of the EPROM or PROM.
OGAWA TAKAO
ONO MAKOTO
