Got a question....PDP? VAX?

From: Dean Billing <drbilling_at_ucdavis.edu>
Date: Mon Mar 15 12:10:53 1999

At 10:14 AM 3/14/99 -0500, you wrote:
>On Fri, 12 Mar 1999, Jason Willgruber wrote:
>>What I'm wondering, is what exactly is a PDP, or a VAX, or an Altair, or any
>>...
>
>The PDPs were DEC's series of processors. The PDP-8 and -11 were most
>successful. The processors were used in a wide variety of machines. The
>VAX is DEC's first 32-bit machine. It used an OS called VMS, which some
>people like a lot for some reason, to the point of still using it.

The reason some people like, and still use, VMS is because it is an
industrial strength operating system, just like big IBM mainframe operating
systems. It is extremely reliable, robust, predictable, well documented,
easy to use, dependable, stable and well supported. A VMS system will run
for many months, even years, without crashing and when it does, it is
usually a hardware problem. It has one other feature no operating system
has yet, true clustering. You can grow huge systems modularly and only
have to maintain one system disk.

>I heard that NT has a lot of VMS engineers behind it.

This statement might be somewhat true. After M-Squish designed NT, they
hired one of the VMS gurus from DEC and while there have been many
modifications to NT to add more VMS like features, it has one giant
drawback, the underlying operating system is UNIX based, the Mach kernel.
Therefore, they have not been able to implement a true clustering system
and IMHO because the DEC software engineers came late to the game, they
were unable to design the basic reliability into the operating system
software interfaces. NT servers usually crash regularly, i.e. in less than
a week, sometimes several times a day, especially if anyone is doing
development work on them. Another drawback to NT is that many software
upgrades and application installation/deinstallations require rebooting,
something unheard of with VMS.

-- Dean
Received on Mon Mar 15 1999 - 12:10:53 GMT