Macintosh IIcx (Mac IIcx) A version of 's , introduced in 1989, with a processor running at 16 MHz and up to 128 MB of (120 ns, 30-pin chips). The IIcx requires System 6.0.3 or later and requires "Mode 32" or "32-bit Enabler" to use more than 8MB of RAM. It was discontinued 1991, and in 1996 is still considered one of the best-designed Macs ever. (1996-05-25)