compilers in assembly - Re: Right toolf for the job (Was: teaching programming to kids

Hi I can't recall exactly but I had a NC4000 CPU with less than 4K words in ROM and about 1K words for the compiler that could completely recompile it self in about 17 seconds ( including compiling the compiler-compiler ). The NC4000 was running a 4MHz with a old XT HD controller and a 5 Meg hard disk. Of course, it was an optimized Forth processor and could run two memory busses at the same time. It used a variant of Forth call CMFORTH. It was vary simple and had no states like many Forths. It had two interperters, one for interactive and one to compile. While a Forth interpreter could be completely written in assembly, I've not seen it done. It is quite trivial and can only really benifit from an assembly language dictionary search as the rest has vary little overhead. Such and interpreter would look like: Parse out a word from the input stream See if it is in the dictionary If so execute it If not see if it is a number If so put it on the stack else report error and stop Repeat. You'll note that there is no funny business about checking to see what comes first, just do it as you come across it. It has no need for recursive interpretation. In a sense it is just like machine language with unlimited macro power built in. It make no distiction between machine level code and threaded code ( could even be call threaded ). Dwight