The MIT Lisp Machine microcode feels like writing in a modern 3-address RISC instruction set to me. I see a lot of reluctance to modifying the source in old mai

The MIT Lisp Machine microcode feels like writing in a modern 3-address RISC instruction set to me. I see a lot of reluctance to modifying the source in old mailing lists, maybe everyone was told that it was too hard so didn't try. EDIT: An example: The CADR has a nice API from Lisp to the CHAOSNET hardware, the microcode wakes up a stack group (thread) and passes it a buffer to process. Later machines had Ethernet but there isn't any microcode support for the hardware, Lisp code just polls the status of the ethernet controller and copies packets around a byte at a time. The microcode buffer handling routines for CHAOSNET could have been reused for Ethernet.