Abstract : This paper analyzes the hardware architecture of the FANUC 3MA CNC machine tool, aiming to fully utilize its functions. Based on this, serial communication software between the microcomputer and the XK5040-1 is further developed, replacing the original paper tape reader and punching machine. Keywords: Interface communication; Software Introduction Since the development of the first three-axis CNC vertical milling machine by MIT in 1952, and especially with the advent of microcomputer CNC in 1974, CNC machine tools have achieved rapid development. The FANUC 3MA CNC system still holds a considerable market share in China's manufacturing industry. The XK5040-1 produced by Beijing No. 1 Machine Tool Plant uses the FANUC 3MA CNC system. This CNC system is used in small CNC milling machines with moderate functions. Originally, it was mainly used for machining boxes, holes, and some simple curved surfaces. Its program reading methods could only use photoelectric readers and magnetic tape drives, which were bulky, had limited information capacity, slow transmission speed, and were prone to errors. This article introduces a newly developed hardware and software interface between a microcomputer and a CNC milling machine (RS232C). This interface improves the programming efficiency and data transmission reliability of CNC machine tools, laying a solid foundation for future DNC development. 1. Hardware Analysis of the 3MA System The FANUC 3MA CNC system was developed in 1980 and introduced to China in 1986. It is a high-precision, high-performance CNC microcomputer control system with embedded software, capable of continuous three-axis control. The 3MA system adopts a separate structure, with the operation panel, system motherboard, servo control unit, motors, and other external devices all provided as separate units. This facilitates user selection based on different machine tools and easily achieves mechatronics integration. The system motherboard uses an INTEL8086 microprocessor, dedicated large-scale integrated circuit chips, and semiconductor memory, significantly reducing the number of circuit components. [b][align=center]For more details, please click: Implementation of Communication between the 3MA System and the Microcomputer[/align][/b]