P-Code

P-Code refers to an alternative means of compiling Pascal programs, where the compiler does not produce code which runs on the machine it is intended for (usually the machine it is compiled on). Instead, it produces a code representation of the program which is then compiled to code which can directly execute on the target machine as a binary executable, or as interpreted code which is run by a software emulator.

The practice began with the Pascal P4 compiler, which produced assembly language for a hypothetical stack machine, which was translated into the object code for the machine. UCSD Pascal took this a step further by creating an entire run-time environment in which the P-Code it generated was executed in that environment as if it was the actual machine code for that machine.