A “UNIX processor” is a CISC cpu, for example the Motorola 68000. In contrast to LISP CPUs like the “TI Explorer” or Forth CPUs like the J1 it has a very complex design, which contains lots of registers, stackframes and microcode. UNIX CPU’s are sometimes called “compiler friendly” because it is easy to write a C and C++ compiler for that hardware. A C++ compiler for example, needs many registers which is not needed by the Forth language or by LISP. The machine code of CISC CPUs has usually a two-adress-scheme, that means the typical assembly opcode like “mov $04, $02”
Was Tanenbaum right?
In the year 1992 Tanenbaum started a flamewar in the internet with the title “Linux is obsolete” in which he criticized the Linux kernel as outdated. The mainstream media has came to the conclusion that Tanenbaum was right, because Linux is programmed in the C programming language and runs only on UNIX processors. The problem with CISC architecture is mainly, that it is something which has to be overcome. It was over decades a nice tool, but a modern computersystem looks different. Also, the programming techniques of implementing Linux in C looks as amateur work compared to what the Forth community is doing.
Nothing against the Linux/Unix project, it is a wonderful community, but it is somethiing which is located in the past. It slows down the development. The future looks different from the harvard architecture. The future is based on stackmachines written in Forth only. How exactly the future in computing will look like is unclear, but it is important to determine which people are leading the revolution and which not. Linux is something which is to slow for future computing, it is a failed project. Linux has lost the race. In contrast, the Forth community is in front. Forth is according to the name, the 4th computergeneration, which is better than the previous one. It is a new kind of hardware, software and programming style with increased productivity.