Why use U* over VMS

[Ed McGuire]

In article <1809.272c3135 at dcs.simpact.com> kquick at dcs.simpact.com (Kevin Quick, Simpact Assoc., Inc.) writes:

> VMS is specific to Digital machines, whereas Unix is forced to be much
> more general.

In article <12234 at medusa.cs.purdue.edu> smb at tristram.cs.purdue.edu (Scott M Ballew) writes:

> Actually, since Unix was originally designed for DEC machines, this is
> not a valid statement.  The difference really lies in the philosophy
> underlying the systems' designs.

This is pretty misleading.  UNIX was originally developed for the
PDP-7, not the VAX-11.  These are a very different.  UNIX was later
ported to the PDP-11, and to the VAX-11 when it was released.  More
recently, it was ported to MIPS (the heart of the DECstation:  not a
Digital chip though).  All these machines have different CPU
architectures.

VMS was designed for and around the VAX-11.

Both claims are essentially correct:  VMS is specific to and optimized
for the VAX architecture, but probably could not be ported to anything
else.  UNIX was designed to be ported easily to another CPU, but cannot
take advantage of all strengths of the architecture.  And these
differences are clearly reflections of different design philosophies.

Though take a look at the modern PDP-11 sometime.  RSTS/E provides a
significant subset of the "look and feel" of VMS on a PDP-11.  Hats off
to those guys.
-- 
peace.  -- Ed
"Just under half the DEC vice presidents who report to Senior VP Jack Smith are
named Bill."  -- Digital Review/October 22, 1990