Re: Programming languages for the very young

From: Michael D. Ober (obermd-._at_.-alum-mit-edu-nospam)
Date: 01/30/04 

Date: Fri, 30 Jan 2004 07:10:55 -0700

"Joe Marshall" <jrm@ccs.neu.edu> wrote in message
news:3c9yep0t.fsf@ccs.neu.edu...
> "Michael D. Ober" <obermd-.@.-alum-mit-edu-nospam> writes:
>
> > The last time I looked, all processors except the IBM mainframe
processors
> > have machine level SUB and RET instructions. These are the two
instructions
> > required for subroutines.
>
> You only need a conditional branch to get subroutines. It's a pain,
> but you can do it.

Actually, BAL does it with unconditional branches. My point was that
subroutines are part of the stack machine model that just about every
processor uses and that processors support them in machine code.

Mike.