SCII (Mac or PC) supports the 4 following memory configurations:1) 8 Mb (two SIMMS)2) 16 Mb (four SIMMS)3) 24 Mb (six SIMMS)4) 32 Mb (eight SIMMS)SIMMs must be: 4Mb, 70ns (or faster), 30-pin.Parity or non-parity RAM isn't a factor, because SCII doesn't make use of parity.