[Info-vax] Emuilation (Was:VMS Software Inc. OpenVMS 8.4-1H1 Boots on i4 System)

[Chris Scheers]

lists at openmailbox.org wrote:
> 
> Really, emulation is not a substitute for real hardware in production.
> Emulators can be excellent development platforms but at the end of the day
> software has to run on real, buggy hardware for a long time to know if it
> works. To my knowledge nobody has enough clinical data on emulators to run
> them safely in production whether they perform better than real hardware or
> not.

Actually, there are very good reasons to use emulation in production.

Ones that quickly come to mind include:

1) Custom hardware
2) Custom software
3) Certifications
4) Reduction in power/cooling/footprint

Honestly, if you can port your application to a newer platform, you are 
probably better off doing so.  However, this isn't always possible.

Disclaimer: I support a commercial emulator for Data General systems.

We have seen locations that spent years and (I suspect) millions of 
dollars trying to port 30 year old code where everyone involved either 
died or retired.  When the attempt at porting can't do the job that a 30 
year old computer is doing, emulation becomes a very real option.

This includes life/safety critical systems.

Item (4) can be of surprising value.  When you can replace 5 or 6 
cabinets in a data center that has no more room for expansion with a 2U 
box, the ROI is quite impressive.

Also note that running "better" than real hardware is not usually a 
concern.  Quite often, the need is to run identically to the real 
hardware.  (The definition of "identically" is project specific.)

-- 
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Chris Scheers, Applied Synergy, Inc.

Voice: 817-237-3360            Internet: chris at applied-synergy.com
   Fax: 817-237-3074