🚀 go-pugleaf

In article <1992Apr9.174633.3940@mahendo.jpl.nasa.gov>, robert@triton.jpl.nasa.gov (Robert Angelino) writes:
> Dec World,
> 	I'm trying to convince some managers to off-load some of the
> CPU on the VAX by getting DECstation 5000s and connecting them on 
> a network so that the two machines (VAX and DECstation) can talk
> to each other, exchange files, compile and run the same programs, etc..
> I know DECstations run Ultrix, but how compatible are the two OSs???

How compatible are VMS and ULTRIX?  Not very, but it depends on what
you're doing.  You'd have a hard time running a DCL command procedure
on an ULTRIX system, be it VAX or MIPS.  Various VMS layered products
do a fair job of hiding incompatibilities.

> Can I access files from the VMS system without having to tell it to
> go to the DECstation disk and vice versa (something like NFS on VMS)??

Look at UCX.  Among it's features are an NFS server for VMS.

> Can I port my VMS program to the the DECstation without changing
> anything???  

That depends on how portable your programs are.  Do they take advantage
of any VMS system services or run time libraries?  Any compiler extensions
the VMS compiler support?

> Do I have to worry about byte order and fun stuff like that??   

Not byte order.  Floating point format yes, but not byte order.

> How compatible are binary files???

Depends on the binary data.  If they're nicely aligned integers you
shouldn't have any problem.  Floating point numbers are another matter,
but if you're using FORTRAN there's a feature a DEC FORTRAN that will
do the conversion for you.  Complex data structure are the hardest part
because the VMS languages don't enforce any sort of reasonable data
alignment, unless you explicitly tell them to (VAX C).  The DECsystems
though like seeing well aligned data.

> Can I download a VMS
> binary file with varirable length records and have the DECstation
> able to read it with problems???

You'll probably have to write a program that understands variable
length records and do something reasonable with them.

> Can I do all these thngs with
> the system (DECstation) out of the box or am I wishful thinking???

If your program is portable and you're only using nicely aligned
integer binary data, then the odds are good.  If you're using
VMS system service and run time library stuff, have complex data
structures that include floating point number and poorly aligned
data, the odds are bad.
> 
> Any responses are welcome.
> -- 
-- 
Alan Rollow				alan@nabeth.cxo.dec.com