IBM Corp’s Personal Computer Co duly introduced those enhanced versions of the PS/2 Models 56 and 57 Micro Channel systems, which can achieve performance improvements of up to 40% over their predecessors, depending on the application; they use IBM’s conservative 75MHz/25MHz clock tripler with 16Kb cache, and come standard with 8Mb; called the PS/2 56 and 57 486SLC3, they have XGA-2 graphics and are available with 170Mb, 245Mb or 340Mb drives, and there is a 540Mb for the PS/2 57; PS/2 56 medialess models also are available for Token-Ring and Ethernet; prices for a fully configured PS/2 56 or 57 go from $2,300.