[comp.sys.ibm.pc.rt] Floating Point Processer not accessed?

RFY630@MAINE.BITNET (Chris Winne) (08/02/90)

We have a RT6151, with an advanced processor card and floating point
accelerator.  However, when I issue the command fptype, the machine
tells me I am using software emulation.  The floating point accelerator
has been installed with devices, and it checks out fine using
diagnostics.  I don't think it is really working however, since similar
(image processing) programs take at least as long on this machine as on
a zenith-286.  The only strange thing I can find is in installation
configuration, it finds the APC card and the FP card both in slot A,
with nothing in slot B.  Any suggestions (Why else would I write?)?
 
Chris Winne RFY630@Maine (bitnet)

marc@stingray.austin.ibm.com (Marc J. Stephenson/140000;1C-22) (08/03/90)

You sure you got that right?  When the command 'fptype'
tells you that it is using software emulation, then that
matches the configuration for a ROMP (not APC) without
a floating point accelerator.  There are 5 configurations:
   ROMP, no FPA = software emulation
   ROMP, FPA I = FPA I
   ROMP, FPA II = Advanced floating point accelerator
   APC, no FPA or FPA I = MC68881 (overrides FPA I, if there)
   APC, FPA II = Advanced floating point with DMA (best combo)

Run dbx on anything (even /etc/passwd), run the 'registers'
command, and see how many floating point registers show up.
If it shows 32, you've got an FPA II, 8 + status = MC68881,
7 + status = FPA I or software emulation.

I don't understand your diagnostics results.

--
Marc Stephenson (marc@stingray.austin.ibm.com)
DISCLAIMER: The content of this posting is independent of official IBM position.
External: uunet!cs.utexas.edu!ibmaus!auschs!stingray.austin.ibm.com!marc
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RFY630@MAINE.BITNET (Chris Winne) (08/07/90)

I'm making some progress, but it is still a bit puzzling:
 
 
 
The machines DOES have an APC card with a Floating Point accelerator.  I
 
have discovered that if I check out the floating point accelerator with
diagnostics the command fptype will return the proper configuration (it
may be all I have to do is load diagnostics, but I havn't slimmed down
my testing that far yet), i.e. Floating Point Type = APC Card with
MC68881.  However this seems to be dropped after awhile (sometimes when
PCSIM bombs, otherwise after normal shutdown).  When software emulation
is indicated, dbx shows 7 + status floating point registers, when APC
Card with MC68881 is indicated, dbx shows 8 + status floating point
registers.  The file /etc/master shows floating = hardware nomatter what
fptype returns.  I know this seems strange, but that's the way it is.