Q. Origin of RISC?
In the 1980s a new philosophy developed having optimizing compilers which could be used to compile 'normal' programming languages down to instructions which were as simple as equivalent micro-operations in a large virtual address space. This made instruction cycle time as rapid as the technology would allow. These machines must have simple instructions such that it can harness potential of simple instruction execution in one cycle - So having reduced instruction sets - henceforth reduced instruction set computers (RISCs).