Subject: Re: VAX 6400 booting saga: SUCCESS!
To: Gunther Schadow <gunther@aurora.regenstrief.org>
From: Johnny Billquist <bqt@update.uu.se>
List: port-vax
Date: 03/19/2002 10:02:19
On Mon, 18 Mar 2002, Gunther Schadow wrote:

> Johnny Billquist wrote to der Mouse
> 
> >>But even then, you don't need an "ieee floating point package", just
> >>converstion from IEEE to VAX.  (And back, if you want to generate
> >>bytecode compatible with IEEE JVMs.)
> >>
> > Which also is what I said. And storing in ieee is neccesary, or the next
> > read will screw you up as well.
> 
> 
> So, then what is the problem? You hack the bytecode parser (and all
> java.io.DataInput, DataOutput etc.) to convert floats from and to VAX
> format. That makes you 100% binary compatible for reading and writing.

Yes, as long as you don't get one of those ieee values which there isn't
a represenation for in the VAX fp formt.

> The *only* thing that will cause trouble are those rare cases where
> a Java program actually messes with the binary format (like the
> Float and Double toString and parse routines.) Those need to be
> rewritten for the VAX. But it's quite unlikely that many other
> software messes with the binary format.

I hope so, but that is another potential problem.

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol