The MSC1209 is a Bi-CMOS display driver for a 1/2-duty vacuum fluorescent display tube. The MSC1209 consists of an 84-bit shift register, an 84-bit latch circuit, a 10-bit digital dimming circuit, 42-bit segment drivers, a 2-bit grid circuit, and a cascade control circuit. The MSC1209 is interfaced with a microcontroller by using three signal lines of LOAD, CLOCK, and DATA. The cascaded MSC1209 ICs can share LOAD, CLOCK, and DATA.