Re: Have you read this?

[Chuck Lewis <clewis@xxxxxxxxxx>]

Oh I'm SURE I'm missing the point :-)

I was just noting that it WAS there because some folks seemed to not be sure :-)

Chuck

leif@attglobal.net wrote:

> Chuck,
>
> You are missing the point:
> 1) The CPU has one of the most powerful FPUs around
> 2) The use of this FPU can be disabled in software by setting
> a bit in the MSR (Machine State Register).
> 3) This 'disable' bit is set (at least on the low-end models)
>
> So, the customer is paying for hardware that he has,
> but cannot use it. An interesting issue is to what
> models this apply. Only low-end, or all, or what?
>
> BTW, the FPU can be enabled again in software...
>
> > OK from reading the book "Inside the AS/400" by Frank Soltis (EVERYONE that
> is
> > interested in the AS/400 SHOULD read this book !!!), page 43-44, etc.
> Muskie
> > (A30) DID have FPU... So the 530 and 53S had it...
> >
> > Chuck
> >
> > leif@attglobal.net wrote:
> >
> > > > except that on some (all?) AS/400 models, the PowerPC floating point
> > > > unit is disabled while running OS/400. So the calculations would run
> > > > very slowly with emulated floating point operations.
> > > > ---------------
> > > > I find it a little difficult to believe that Rochester would design
> what
> > > they
> > > > call "IBM's fastest floating point processor" for the old Muskie chip
> sets
> > > and
> > > > then turn the thing off in all of those 530 and 53S machines.  Maybe
> the
> > > FPU's
> > > > are turned off in low-end machines - that would be about par for the
> way
> > > IBM
> > > > screws us over to create their bloody "price points" - but in all
> models?
> > > That
> > > > doesn't seem reasonable.
> > >
> > > I have actually only confirmed this on low-end modes. I don't know about
> > > the high-end (that why the 'all' had a ? next to it). I was hoping from
> some
> > > input from IBM lurkers on this.
> > >
> > > About the fast FPU, don't forget that it is also used on AIX.
>
> +---
> | This is the Midrange System Mailing List!
> | To submit a new message, send your mail to MIDRANGE-L@midrange.com.
> | To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
> | To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
> | Questions should be directed to the list owner/operator: david@midrange.com
> +---

+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---