Don't Nurse Old Hardware - Emulate It

gManZboy writes "Bob Supnik, former team lead for DEC's VAX microprossesor, has an article up on Queue about his Computer History Simulation Project and how emulating old servers may be a better way to keep them running that servicing the physical machines. So how many PDP-11's can you run on a Pentium 4 anyhow?"

Comments

Emulation is great ..

[z0ink]

.. but you forget the reason people dont upgrade is that it costs money to do so.

Re:Emulation is great ..

[Halo1]

The large cost of upgrading is not the hardware cost, it's the migration cost. If your new hardware can emulate exactly the same environment where you came from, this cost can be reduced immensely.

Good idea... but...

[AdeBaumann]

Before I even R'd TFA, I thought about one big problem:

How are you going to emulate a 5.25 inch drive to read old disks?

The Stability of New Products vs Old

[Anonymous Coward]

Although this is a very good idea I question the stability of a new emulator vs an old proven system.

By using the original the kinks have already been worked out, quirks are known and understood, and everything just works.

By creating an emulator you have bugs to smash, that's just the way software is. Also keep in mind this seems to apply to big businesses (financial, medical) and large organizations (NASA) with legacy hardware. Since the stability of these systems is absolutely crucial why would they want to switch to a new, unproven, buggy system that stick with the old?

Re:The Stability of New Products vs Old

[GeoGreg]

Well, for one thing, the old, (formerly) stable hardware may be failing. It might be easier to get hold of a PDP/11 emulator being used (and, hopefully, improved) by multiple organizations than to attempt to translate the in-house PDP/11 assembly code into something that will run on a PIV Linux box. Especially if the people who wrote the legacy app are retired/laid off/dead.

Re:The Stability of New Products vs Old

[quarkscat]

There is no equivalence. For instance, DEC VMS
was used as the design "core" for Microsoft's
Windows NT. I have known of DEC VAX hardware
that ran continuously for 5 years without a
warm reboot, let alone a system shutdown. The
Microsoft OS often needed to be rebooted daily.

The hardware that Microsoft runs on is not as
reliable as the old DEC VAXs, as a rule. The
short term emulation of a legacy system is not
the same as replacing it. For exammple, an IBM
z/390 running MVS might be able to run 1000
linux servers, but in terms of reliability
(the proverbial 5 Nines), that z/390 could not
be replaced with 1000 linux boxes, or even 2000.

The old adage "They just don't make things the
way they used to." applies here. New hardware
costs are way down, as are HW/SW maintenence
costs, but the reliability of the new gear is
underwhelming.

I wonder why...

[5m477m4n]

by Bob Supnik, Sun Microsystems

Gee, I wonder why he would be recommending buying new servers?

Re:Can't believe no one's thought of this

[PhilHibbs]

It's not like there is some pool of emulator writers, constantly considering what the world needs in terms of emulators. The people that write GBA emulators are people that want a GBA emulator. Asking them nicely to write a Pr1me emulator is likely to get you nowhere. You need to talk to the people that want a Pr1me emulator.

Re:DEC VAX -- why not port?!

[CarrionBird]

just upgrade the software?

Methinks you underestimate how badly software projects of that sort often go.