Hi all,

On Oct 28,  7:55pm, Thomas G Cook wrote:
...
> But, HP has announced a new 64 bit MPE and a host of new product
> improvements.

There have been many references to a "64 bit MPE" on this list and in
some publications.  I'd like to quote from Harry's announcment at HP World:

    "While we're on the subject of the PA 8200, I'd like to
     revisit some remarks I made at last year's HPWorld
     conference in Anaheim.  At that time, I said we were
     continuing to investigate the need for 64-bit functionality
     in a new version of MPE -- one that would fully exploit the
     power of the new PA-8000 processors.   At that time, it
     wasn't clear that a business need existed for a 64-bit HP
     3000 operating system.  But I said we would continue to look
     into the matter.

     After better understanding your future needs, our continued
     investigations have now convinced me that we need to move
     forward on this front.  In order to meet the performance and
     growth needs of our customers, it's now clear that we will
     need 64-bit memory and storage management.  And so we have
     recruited some of the top engineering talent in Hewlett-
     Packard to join us in CSY to work on a version of MPE/iX
     that will fully exploit the 64-bit PA-8000's architecture.
     As we get further along in these areas, we'll be able to
     announce specific enhancements that will result. "

There are many definitions of 64 bitness in an operating system.  Having
64 bit virtual addresses and few applications that use them can actually
*slow* down performance due to cache "pollution" -- that is, more cache space
is consumed due to lots of addresses with 32 bit of zeros.

MPE/iX has supported 64 bit addresses (long pointers, with 32 bit offsets)
since day one.  Currently MPE/iX is restricted to 3.75 GB of physical
memory and one of our goals is to break this barrier using some 64 bit
techniques.  Also, even though PA8000s have 64 bit general registers, today
MPE does not exploit this, but in the future we will.

We will use 64 bitness where it makes the most sense, keeping in mind the
tradeoffs for the majority of our customers who are on PA7x00 (non-64 bit)
systems.

Regards,
Jeff Vance, CSY

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