Complex sentence: The System/360 combined the best features of the 7000 and 1400 series architectures into a single design, however some 360 models had optional features that allowed them to emulate the 1400 and 7000 instruction sets in microcode.
Split into simpler sentences: The System/360 combined the best features of the 7000 and 1400 series architectures into a single design. However, some 360 models had optional features that allowed them to emulate the 1400 and 7000 instruction sets in microcode.