-1 and friends

[Mark H. Wood]

On Sat, 9 Sep 2000, Gert Doering wrote:
> On Fri, Sep 08, 2000 at 06:14:01PM -0700, Gary E. Miller wrote:
> > On Fri, 8 Sep 2000, Garance A Drosihn wrote:
> > > At 3:46 PM -0700 9/8/00, Gary E. Miller wrote:
> > > >I would also like to argue for more orthogonality between scp,
> > > >ssh and sshd.
> > > 
> > > I suspect you did not want to ask for "more orthogonality"...
> > Yes I did.  This is the lingo CPU designers us when they mean that
> > they want a class of instructions to look similar.
> 
> Actually, "orthogonal" in mathemathics and physics means exactly the
> opposite: a set of vectors being orthogonal means all of them are at
> right angles to each others, the scalar product being zero...

That's what it means in CPU design, too:  it means that various attributes
of the instructions are independent.  Like the way most of the PDP-10
instruction set has all the same addressing modes, regardless of the
operation performed, even when it "makes no sense"  (SET and JUMP are both
no-ops, and SETMM is another no-op except that it exercises the path to
memory.)  I wouldn't have used the word the way he did, but it makes a
kind of sense:  the options are independent of the underlying operation --
the two semantic vectors are orthogonal.

I tend to think this would not be a bad thing, but then the PDP-10 is
still my favorite architecture because it's so consistent....

-- 
Mark H. Wood, radical centrist     OpenPGP ID 876A8B75     mhwood at ameritech.net
01/01/00 00:00:00 -- Apocralypse Now