gauging interest in VAX 6000-530

From: Mike Cheponis <mac_at_Wireless.Com>
Date: Mon Oct 25 02:04:34 1999

> On or about 07:56 PM 10/24/99 -0700, Mike Cheponis was caught in a dark
> alley speaking these words:
>
> >That's fascinating. Take obsolete hardware and architecture (vax), and
> >keep them running! I guess I will never cease to be amazed at the weird
> >things people do. Heck, I heard the other day that people are -still-
> >running 1401 emulation mode under a VM/360 simulator on their modern h/w!
>
> The last three places I worked for (or heard of thru the grapevine) were
> running mostly System 36 RPG apps in emulation on their AS/400 hardware...
> it's more common than you might think!

I think somebody mentioned that "if it works, don't touch it!" is a
prevalent (and not crazy) business strategy. That makes sense to me.


> >> Its not the speed
> >>of the individual bus, but its the number of busses.
> >
> >That's of course bull.....

In case you didn't notice, there were some sentences after that statement...

>
> You crack on others for stating things without backing up with actual
> data... where's yours? My wife's box is a Pentium 100 running SCSI3Wide and
> I did benchmarks (real-world... but don't have them handy) which showed
> that box stomped a Pentium 166 / IDE. (Mind you, saying the IDE bus is
> rather an oxymoron, as it's an extension of the ISA bus IIRC... :-)

> The difference? The IDE bus is totally stupid (read: CPU controlled)
> whereas the SCSI bus is very smart (read: 80Mhz RISC CPU controlled) - the
> SCSI controller is offloading most of the CPU overhead.

Hey, I think PC busses are stupid. It's taking a long time just to get
to semi-reasonable busses, but that's the way it is.

IDE is a particularly insidious bus. The electrical specs are not well-
defined, and there are a panoply of "modes" PIO Modes 1,2,3,4, UDMA Mode 1
and Mode 2, etc.

AFAIK, UDMA Mode 2 is actually as fast as UW SCSI II for a single disk drive;
of course, people use SCSI for multi-spindle applications as well as high
throughput.


> Despite all this, the mouse driver on it right now sucks wind, and can lock
> the entire machine for over 3 seconds... bad driver/bus design. That's
> something the PC world will prolly never get rid of.

Sounds like a s/w problem. Eject the virus, run Unix.


> Tho I've never seen, touched, smelled a Vax, I've seen other DEC hardware
> (yes, even a 3-CPU 486DX33) that use sub-controllers for all of their I/O,
> and they handled lots of multiple users wonderfully, and if one I/O
> controller goes south, the equipment is designed to continue with minimal
> heartburn.

I've used a PDP-1, PDP-5, PDP-6, PDP-8, PDP-9, PDP-10, PDP-11, PDP-12,
PDP-15 and VAX-11/780, VAX-11/750, VAX-11/785, and VAX-11/8600. I love DEC!
I used to work for them!

But their machines are obsolete, and that's why we're discussing them here.


-mac
Received on Mon Oct 25 1999 - 02:04:34 BST