"The method used to create the first Pascal compiler, described by U. Ammann in The Zurich Implementation, was to write the compiler in a subset of unrevised Pascal itself, then hand-translate the code to SCALLOP, a CDC specific language. The compiler was then bootstrapped, or compiled using the Pascal source code and the SCALLOP based compiler, to get a working compiler that was written in Pascal itself. Then, the compiler was extended to accept the full unrevised Pascal language."
http://pascal.hansotten.com/niklaus-wirth/cdc-6000-pascal-co...
"The method used to create the first Pascal compiler, described by U. Ammann in The Zurich Implementation, was to write the compiler in a subset of unrevised Pascal itself, then hand-translate the code to SCALLOP, a CDC specific language. The compiler was then bootstrapped, or compiled using the Pascal source code and the SCALLOP based compiler, to get a working compiler that was written in Pascal itself. Then, the compiler was extended to accept the full unrevised Pascal language."