[comp.sys.apollo] Problems with FTN 10.[78] / 425t

bergstr@SSDC.HONEYWELL.COM (-Darryl Bergstrom Apollo/Symbolics/News/Mail Administrator) (06/22/91)

We are having some strange results from some simulations running on a 400t and 
a 425t.  I was wondering if there are known differences with the math done on 
a 68882 -vs- 68040.  The results that follow are using FTN 10.7 / SR10.2.4 
(10.8 on 10.3.4 provided similar results)...

norm: 400t SR 10.2.4 
  
  iday= 160 clk= 0.0000000 tsen= 78.00000 tair= 0.0000000 err2= 0.0000000 stat= 1
  iday= 161 clk= 4.4386904E-03 tsen= 77.81004 tair= 78.03871 err2=
-0.1899567 stat= 0
  Total duration of fan over-run =  134.6400063950568 minutes
 Integrated total cooling capacity =    69.075 kWh =    235754. btu
  
clavin: 425t SR 10.3.4
 
  iday= 160 clk= 0.0000000 tsen= 78.00000 tair= 0.0000000 err2= 0.0000000 stat= 1
  iday= 161 clk= 3.4386902E-03 tsen= 77.82001 tair= 78.07195 err2=
-0.1799927 stat= 0
  Total duration of fan over-run =  162.3600077116862 minutes
 Integrated total cooling capacity =    83.005 kWh =    283297. btu
 
 
Any ideas? (hmmm.... nick here says that JT from SSEC.honeywell.com will be
the first to reply.   The stop watch is running....)

-Darryl Bergstrom   Apollo/Symbolics/News/Mail Administrator
-Honeywell SRC/SSDC IS Minneapolis, MN
-bergstr@ssdc.honeywell.com

erstad@PAN.SSEC.HONEYWELL.COM (Dave Erstad) (06/24/91)

      
>We are having some strange results from some simulations running on a 400t and 
>a 425t.  I was wondering if there are known differences with the math done on 
>a 68882 -vs- 68040.  The results that follow are using FTN 10.7 / SR10.2.4 
>(10.8 on 10.3.4 provided similar results)...
      
Yes, we've seen numerous changes in arithmetic results.  Nothing as large
as the example cited, but that might be application dependent, depending
on the stability of the calculations.  This is with C and Pascal 
applications.

We did receive a patch OS from HP/Apollo which appears to address many 
of the inconsistencies:

        **** Node 29D5E.2E747 ****   "//isildur"
   Domain/OS kernel(11), revision 10.3.4.3, test  May 16, 1991  8:41:55 am
                                            ^ Never had an OS say that before!

       
>Any ideas? (hmmm.... nick here says that JT from SSEC.honeywell.com will be
>the first to reply.   The stop watch is running....)

Well, I haven't seen him today so I might have him beat.  He is engaged,
you know   :-)

But I suspect he'll have some more concrete info to add.

Dave Erstad
Honeywell SSEC
erstad@pan.ssec.honeywell.com