HD68B21P is a (100% tested / refurbished) Hitachi PIA, 2Mhz, DIP-40 Package. 6821 Peripheral interface adapter (PIA) provides the universal means of interfacing peripheral equipment to the 6800 family of microprocessors. These are 100% tested working chips. These are used in many arcade and pinball applications such as Bally AS-2518-17 and AS-2518-35 MPU and many other applications that use this chip. This 6821 PIA can replace any of the following 1Mhz, 1.5Mhz or 2Mhz PIAs: MC6821L, MC6821CL, MC68A21L, MC68A21CL, MC68B21L, MC68B21CL, MC6821P, MC6821CP, MC68A21P, MC68A21CP, MC68B21P, MC68B21CP, MC6821S, MC6821CS, MC68A21S, MC68A21CS, MC68B21S, MC68B21CS, HD6821, HD68A21, HD68B21, HD6821P, HD68A21P, HD68B21P, 6820, 68B21, HD63B21P, HD6321FP, EF68B21P, HD68B21P, MC68B21P, Bally E-620-29, Williams 5A-8972, Williams 5430-08972-00, Data East / Sega / Stern 100-0255-00, Motorola – MC6821P, ST Microelectronics – EF68B21P, Hitachi HD468B21P, Fairchild Semiconductor – 68B21P, Taito 15-00004-001 and many other part numbers of other manufacturers.