Diagramming Robust AI

Jonah Thomas jethomas at ix.netcom.com
Thu Mar 26 01:45:10 EST 1998


In article <3519E315.689D at ix.netcom.com>,
	"Phil Roberts, Jr." <philrob at ix.netcom.com> wrote:

>Riddle:

>What language was FORTH written in?

Mostly in Forth.  A limited number of "primitives" got
written in 
assembler, and then the rest were done using those
primitives.  People 
argue over the minimum number of primitives.  (Of course
that depends on 
the particular processor.)  One commonly-used system has 31
primitives 
plus five OS calls to make a minimal system.  More
primitives can be 
added for speed.  Some existing primitives can be removed
to get a system that's easier to port to new hardware. 
Obviously, if you want to get 
Forth running on hardware that hasn't been debugged yet,
the fewer the primitives and the simpler the primitives the
easier it is to program 
around the flaws in the chip.

Some people have taken to writing Forths in C so they won't
have to 
rewrite the primitives when they switch to a new system
that already has 
a C compiler.  But traditionally Forths have been written
in Forth and 
assembler.  And typically the first step in writing a Forth
for a new 
system has been to write an assembler in an existing Forth.
 



More information about the Neur-sci mailing list