T89C51AC3 changed from T89C51AC2 - brown out reset - Code 32->64K - Ram 1->2K ref http://www.atmel.com/dyn/products/product_card.asp?family_id=604&family_name=8051+Architecture&part_id=3540
Device already part of V8.01. See: http://www.keil.com/dd/chip/3987.htm