NEC made an enhanced clone of the 8086 called the V30 that had built-in 8080 support. It could be switched in and out of 8080 mode on the fly. This made it fairly simple to write a program that allowed CP/M programs to run natively on an MS-DOS PC with a V30. The MS-DOS API was mostly a copy of the CP/M API, so all you had to do when you got a CP/M system call was switch the CPU into 16-bit mode, do the equivalent MS-DOS system call, and switch the CPU back to 8-bit mode.