Canon card MD-81

Canon introduced in 1979 with the MD-8 the first pocket calculator using a two-line display. The upper display is the usual working display while the lower line shows the memory content or intermediate results. Main disadvantage of this innovative concept was the power consumption of the display and the used TMS1079 microcomputer resulting in a short operating time of the three AA-sized batteries.The Canon card MULTI 81 MD-81 is an arithmetic calculator with 8 digits precision and algebraic logic. It has 10 functions, 28 keys and an LCD (liquid crystal) display. The power source is 2xLR44. The calculator was manufactured in Japan.