Taximeter with tariff display mode controlled by removable memory addressable by fare rate keys

Claim 1

An electronic taximeter comprising: a fare calculation device within the body of said taximeter; a plurality of tariff keys for sending tariff information to said fare calculation device; a tariff display including a plurality of tariff condition displaying elements; a memory device fitted removably to said body of taximeter and containing tariff display enabling and disabling information associated with said respective tariff displaying elements; an address generator for generating an address signal corresponding to an actuated one of said plurality of tariff keys upon actuation thereof; an address circuit for specifying the address of said memory device in response to said address signal produced by said address generator; and means for enabling or disabling said tariff displaying elements according to said tariff condition enabling and disabling information recalled from a particular address area of said memory device as specified by said address signal; said memory device producing an enabling and disabling signal when said address circuit specifies the address in said memory device corresponding thereto; said means for enabling and disabling including bistable latch means for driving said tariff display elements corresponding to the information contained in said enabling and disabling signal; wherein said tariff displaying conditions responsive to actuation of said tariff keys are optionally selectable by exchange of said memory device or changes in the contents of said memory device.