MIPS II / MIPS32 has also been used as a model architecture: it's 32-bit and supported by current gcc (as is the PDP-11).  A short paper on running C programs on the JVM is at <http://www.xwt.org/mips2java/>: you compiled them to MIPS R2K statically linked executables and then compiled the resulting executables to Java.  The regularity of the MIPS ISA made the compiled code decently fast even before the JVM JIT.